Age e¤ects on Consumer Demand An Additive Partially Linear Regression Model
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MBA-English-06
Government __________ Four sector: households firms _________, ____, Government trade __________, and _____ Open economy: has _____ trade trade Closed economy: no _____
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Remember AD = C ＋ I ＋ G ＋ X － M
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Imagine the ______ in the economy is $100. This income means $100 of ______ is produced and in a simple output bought circular model this is all ______ by households who ____ $1O0 and _____ $100. earn spend
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The paradox of thrift
If households try to save more of their income, they may end up saving exactly the same amount of money as before! This is because if they save more of their money, this reduces the level of demand in the economy, which leads to a downward multiplier and a fall in the level of income. Although they may save a greater proportion of their income, because income has fallen their total savings in a two sector economy will be the same total amount as before (because for equilibrium, planned savings must still equal planned investment, which is unchanged).
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Remember AD = C ＋ I ＋ G ＋ X － M
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Imagine the ______ in the economy is $100. This income means $100 of ______ is produced and in a simple output bought circular model this is all ______ by households who ____ $1O0 and _____ $100. earn spend
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The paradox of thrift
If households try to save more of their income, they may end up saving exactly the same amount of money as before! This is because if they save more of their money, this reduces the level of demand in the economy, which leads to a downward multiplier and a fall in the level of income. Although they may save a greater proportion of their income, because income has fallen their total savings in a two sector economy will be the same total amount as before (because for equilibrium, planned savings must still equal planned investment, which is unchanged).
不要吃太多糖 英语作文
In contemporary society, the consumption of sugar has become a significant concern due to its widespread presence in our diets and the potential health implications it carries. The sweet allure of sugar is undeniable, but the excessive intake of this ingredient can lead to a myriad of health issues. This essay aims to explore the reasons behind the high sugar consumption, its effects on health, and the importance of moderation in our diets.Sugar, in its various forms, is a staple in many food products, from soft drinks and candies to seemingly healthy options like granola bars and fruit juices. The sweetness of sugar is a powerful draw, providing a quick burst of energy and a sense of satisfaction. However, the overconsumption of sugar has been linked to a range of health problems, including obesity, type 2 diabetes, and dental caries. The World Health Organization WHO has recommended reducing the intake of free sugars to less than 10% of total energy intake, and further to 5% for additional health benefits.One of the primary reasons for the high sugar consumption is the marketing strategies employed by the food and beverage industry. Companies often use sugar as a way to enhance the taste of their products, making them more appealing to consumers. This has led to an environment where sugarladen products are not only ubiquitous but also aggressively promoted. Additionally, the affordability and availability of highsugar foods make them an easy choice for many, especially in fastpaced lifestyles where convenience is often prioritized over health.The health effects of excessive sugar intake are welldocumented. Obesity,for instance, is a growing epidemic, with sugary diets being a significant contributing factor. The highcalorie content of sugar, coupled with its ability to trigger cravings and suppress feelings of fullness, can lead to overeating and weight gain. Furthermore, the bodys metabolism of sugar can lead to a spike in blood sugar levels, increasing the risk of type 2 diabetes. Dental caries, commonly known as tooth decay, is another direct consequence of high sugar consumption, as the bacteria in the mouth feed on sugar and produce acids that erode tooth enamel.To counteract the negative effects of sugar, it is crucial to practice moderation in our diets. This can be achieved by being mindful of the sugar content in the foods we consume and making informed choices. For example, opting for water instead of sugary drinks, choosing whole fruits over fruit juices, and selecting products with lower sugar content can significantly reduce our daily sugar intake. Additionally, understanding the different types of sugars and their sources can help in making healthier choices. Natural sugars found in fruits and dairy products are generally considered healthier than added sugars found in processed foods.Moreover, education plays a vital role in promoting healthier eating habits. Public health campaigns that raise awareness about the dangers of excessive sugar consumption can encourage individuals to make more conscious food choices. Schools, in particular, can play a significant role in educating children about the importance of a balanced diet and the risks associated with high sugar intake.In conclusion, while sugar is an enjoyable and versatile ingredient, itsexcessive consumption can have detrimental effects on our health. By being aware of the sugar content in our diets and making a conscious effort to reduce our intake, we can mitigate these risks and promote a healthier lifestyle. The role of education, public health campaigns, and individual responsibility in this endeavor cannot be overstated. As we navigate the sweet temptations of modern diets, it is essential to remember the adage, all things in moderation.。
消费者需求变化英语作文
消费者需求变化英语作文In the contemporary marketplace, consumer demand is a dynamic force that continually evolves, driven by a myriad of factors including technological advancements, economic fluctuations, cultural shifts, and environmental concerns. This essay aims to explore the recent trends and underlying causes of these changes in consumer behavior.Firstly, the rise of digital technology has had a profound impact on consumer preferences. With the advent of e-commerce and online marketplaces, consumers now demand convenience and speed. They expect to be able to purchase goods and services at any time and from any location. This shift has led to a significant growth in online shopping, with companies like Amazon and Alibaba becoming household names.Secondly, economic factors play a crucial role in shaping consumer demand. During periods of economic downturn, consumers tend to be more price-sensitive and seek value for money. This has given rise to the popularity of discount stores and the concept of "fast fashion," where affordable, trend-driven clothing is produced quickly and in large quantities to meet consumer needs.Cultural shifts also influence what consumers want. There is a growing awareness of the importance of sustainability and ethical production. This has led to a demand for productsthat are environmentally friendly and produced in a sociallyresponsible manner. Brands that can demonstrate their commitment to these values are increasingly favored by consumers who are willing to pay a premium for ethically sourced goods.Moreover, the demographic changes cannot be overlooked. An aging population in many developed countries has led to an increased demand for products and services tailored to the needs of older consumers. This includes healthcare products, age-appropriate leisure activities, and technology designed for ease of use.Lastly, the influence of social media on consumer demand cannot be understated. Platforms like Instagram and Facebook have become battlegrounds for brands to capture the attention of consumers. Influencers and viral trends can quickly drive demand for certain products, creating short-lived but intense spikes in popularity.In conclusion, consumer demand is a multifaceted and ever-changing phenomenon. Businesses that wish to succeed must stay attuned to these shifts and adapt their strategies accordingly. By understanding the factors that drive consumer behavior, companies can better position themselves to meet the needs of their customers and thrive in the competitive global market.。
商务谈判中的委婉语及其表达方式
商务谈判中的委婉语及其表达方式摘要: 委婉语的使用在商务英语中是一种普遍现象。
它不仅是一种社会语言现象,更是一种文化现象。
文中分析了委婉语与礼貌原则在商务谈判和商务函电中的委婉表达方式，从虚拟语气法、被动语态法、时态倒退法、否定法四个方面归纳分析了商务英语中的委婉表达法，从而使商务工作者“深人字里行间”以求最充分理解和欣赏商务英语的委婉表达方式，从而在商界竞争获取成功。
关键词：委婉语，礼貌原则，商务谈判，委婉表达方式.Abstra ct: Euphem ism expres sionare monlyused in busine ss corres ponde ncesand busine ss negoti ation. whichis not only a social langua ge phenom enon, but it is also a cultur al phenom enon.By making an analys is of euphem istic expres sions and courte sy princi ple used in busine ss corres ponde ncesand busine ss negoti ation s,this papermainly discus ses the fulfil lment of euphem istic expres sions in busine ss Englis h throug h the follow ing four ways: the subjun ctive mood, passiv e voice, tensebackwa rd,negati ve. So the busine ss person nel can fuulyundeer stand and apprec iatethe ephemi sticexpres sionand achiev e a succes s in the petiei ons.Key words：euphemisti c expression; courtesy principle; business negotiation;前言：英语中的委婉语((Euphemism)一词来自希腊语的前缀eu=well和词根phe me=speaking，意思是说好听的话。
如今外卖订餐越来越普遍英语作文
如今外卖订餐越来越普遍英语作文The popularity of ordering takeout food has been on the rise in recent years. With the advancement of technology and the convenience it brings, more and more people are opting to order their meals online or through a mobile app rather than cooking at home or dining out at a restaurant.One of the main reasons for the increasing popularity of food delivery services is the convenience they offer. People can now order their favorite dishes from a wide range of restaurants with just a few clicks on their smartphones. This saves them time and effort, especially for those who have busy schedules or are too tired to cook after a long day at work.Moreover, the variety of food options available for delivery has also contributed to the growth of this trend. Customers are no longer limited to just pizza or Chinese food when ordering takeout. They can choose from a diverse range of cuisines, including Japanese, Italian, Indian, and more. This allows them to explore different flavors and try new dishes without having to leave the comfort of their homes.Another factor driving the increase in food delivery orders is the rise of food delivery apps and websites. These platformsmake it easy for customers to browse through menus, place orders, and track the status of their deliveries in real-time. They also offer features like ratings and reviews, which help customers make informed decisions about where to order their meals from.In addition to convenience and variety, the rise of food delivery services can also be attributed to the changing lifestyles of consumers. With more people living in urban areas and working long hours, cooking at home or dining out may not always be a practical option. Ordering takeout allows them to enjoy restaurant-quality meals without having to leave their homes or offices.While the popularity of food delivery services continues to grow, there are also concerns about the impact they may have on the restaurant industry. Some restaurant owners worry that the rise of takeout orders may cannibalize their dine-in business, leading to a decrease in foot traffic and revenue. However, others see this trend as an opportunity to reach a wider audience and increase their overall sales.Overall, it is clear that the trend of ordering takeout food is here to stay. As technology continues to evolve and consumers demand more convenience and variety in their dining options, food delivery services are likely to become even more prevalentin the future. Whether you are craving a burger, sushi, or a bowl of pasta, you can now have it delivered to your doorstep with just a few taps on your phone.。
Chapter 8 Aggregate Demand and the Powerful ConsumerAP经济学需求理论
• The numerical value depends on the price
level
© 2012 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
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Figure 1
The Circular Flow of Expenditures and Income
© 2012 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
2
Aggregate Demand
• Components of aggregate demand
– Consumer expenditure (C, consumption) – Investment spending (I) – Government purchases (G) – Net exports (X-IM)
level
© 2012 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
10
Figure 1
The Circular Flow of Expenditures and Income
© 2012 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.
2
Aggregate Demand
• Components of aggregate demand
– Consumer expenditure (C, consumption) – Investment spending (I) – Government purchases (G) – Net exports (X-IM)
Chapter 5_Theory of Consumer Behavior
Law of Diminishing Marginal Utility
When an individual consumes additional units of a commodity (X), consumption of other commodities unchanged, the amount of satisfaction derived from each additional unit of commodity (X) decreases.
– Ranking the two bundles, the person can make one of three possible responses: • I prefer bundle A to bundle B • I prefer bundle B to bundle A • I would be equally satisfied with either. – There are three bundles of goods, A, B, and C, if the consumer prefers A to B and B to C, then bundle A must be preferred to bundle C.
5.1 CONSUMER PREFERENCES AND UTILITY
Utility Scarcity Sacrifice and Opportunity Cost Ceteris paribus Law of Diminishing Marginal Utility
Some simplifying assumptions
Opportunity Cost
Since it is difficult to directly measure utility, much can be learned from observing what a person is willing to give up (do without) to consume a particular good or service.
高强度双组分聚氨酯胶粘剂的研制1
研究报告及专论粘 接 2007,28(1)高强度双组分聚氨酯胶粘剂的研制罗纪明,桂武标,杨足明,马德军,夏进强(湖北回天胶业股份有限公司,湖北襄樊441003)收稿日期:2006-06-24作者简介:罗纪明(1967-),男,硕士,从事胶粘剂的研究。
已发表论文20余篇。
摘要:合成了E-己内酯-MOCA 加成物。
以聚碳酸酯二元醇,E -己内酯-MO CA 加成物以及M D I 为主体材料制备的双组分结构胶综合性能优异:剪切强度为27.7M Pa ,180b 剥离强度为5.22k N /m,定位时间为5m i n ,耐温100~120e 。
M OCA 或者E -己内酯-M OCA 加成物在聚氨酯胶粘剂中的含量大于临界含量时,胶粘剂的固化速度明显加快,粘接性能显著提高。
制备的双组分胶粘剂甲乙组分的最佳配比为10B 15.5,此时粘接强度最高,甲乙组分的配比对粘接强度影响较大。
关键词:双组分;聚氨酯结构胶;聚碳酸酯二元醇中图分类号:TQ 433.4+32 文献标识码:A 文章编号:1001-5922(2007)01-0005-03双组分聚氨酯胶粘剂广泛应用于食品包装、纸塑复合、土木建筑以及结构粘接、超低温粘接等场合。
在汽车制造业中已广泛采用塑料、玻璃钢、聚氨酯等作为结构材料,双组分聚氨酯胶粘剂以其优异的抗冲击性、耐久性、耐低温性、耐疲劳性和良好的施工性能而成为首选的胶粘剂。
但是,双组分聚氨酯胶在耐高温性能和粘接强度方面与环氧树脂和第2代丙烯酸酯等结构胶相比还存在较大的差距。
研究高强度双组分聚氨酯胶的国内文献很少,而且强度不高,文献[1]报道的一种双组分胶的剪切强度为14.9M P a ,文献[2~5]报道的最大剪切强度不足11.2M Pa ;瑞士SIKA 公司在其申请的专利[6]中介绍的一种快固型双组分聚氨酯胶的拉伸强度也不超过8.0M P a 。
因此,双组分聚氨酯胶在结构粘接方面的应用受到了很大的限制。
《双语材料翻译》
All ob jects, too ls, c ompon ents, andengin eerin g sys tem r equir e the useof ma teria ls to meet thei r pur poses.所有的物体,工具、元件、工程系统需要使用的材料来满足他们的目的。
The role of m ateri als h as be en su ffici ently impo rtant in t he pr ogres s ofcivil izati on so that theanthr opolo gists(人类学者） and hist orian s hav e ide ntifi ed ea rly c ultur es by thesigni fican t mat erial s.材料的作用已经足够重要的文明的进步使人类学家(人类学者)和历史学家已经鉴定出早期文化的重要材料The se in clude thestone, the bron ze, a nd th e iro n age's of thepast.这些包括石、铜,铁时代的过去。
Withimpro vemen ts in mate rials by t he ar tisan s（工匠） andtechn ologi sts a crosshist ory,it wa s pos sible to m ake i mprov ed pr oduct s.改进材料)和技术人员(工匠艺人跨越历史,才能够使改进的产品。
Tool s wer e mad e mor e ava ilabl e torelie ve to il; h omesweredesig ned f or mo re co mfort; wea ponsbecam e mor e des truct ion,vehic les a chiev ed lo ngerrange s andquic ker t ransp ort a nd ga ve mo re re ady a ccess to f ood,suppl ies,and e njoym ent.工具是更有效地减轻辛劳,你们的家园被设计为更多的安慰,变得更破坏、车辆武器更长寿范围和更快的运输和给更多的准备进入食物供给和享受。
全钒离子液流电池的应用研究
收稿日期:1999 12 22作者简介:崔艳华(1972 ),女,四川省人,助理研究员,硕士。
Biography:CUI Yan hua(1972 ),female,engineer,master.全钒离子液流电池的应用研究崔艳华, 孟凡明(中国工程物理研究院电子工程研究所,四川成都610003)摘要:采用循环伏安法研究了全钒离子液流电池正极溶液的浓度及添加剂对正极反应的影响。
研究了两种离子交换膜对钒电池性能的影响。
结果表明:高浓度的钒离子溶液,其循环伏安表现不理想,而添加剂过氧化氢对还原过程有利。
隔膜研究显示:阳离子交换膜Selemion CM V 有利于提高充放电电流和充电效率,但是机械强度较差,不利于长期使用。
关键词:全钒离子液流电池;循环伏安;添加剂;离子交换膜中图分类号:T M 911 文献标识码:A 文章编号:1002 087X(2000)06 0356 03Research on the vanadiu m ion redox flow batteryCU I Yan hua, M ENG Fan ming(Institute of Ele c tronic Engine er ing o f China Acade my of Engineering Physics,Che ng du Sic h uan 610003,China)Abstract:The effect of concentration and additive of vanadium ion redox flow battery on positive reaction w as investig ated by the means of cycle voltammetry.The results show that the high concentration of catholyte is unfa vorable but the additive H 2O 2is advantageous for reduction.The study on ion m embrane show s that:using the cation membrane Selemion CMV increase the charging efficiency of battery,but it is too breakable to last a long period of time.Key words:vanadium ion redox flow battery;cyclic voltammetry;additive;ion membrane全钒离子液流电池(以下简称钒电池)是一种新型的化学电源,它采用不同价态的钒离子溶液分别作为正负极活性物质,通过外接泵,把溶液从储液槽压入电池堆体内,完成电化学反应。
常用商贸英语缩写
公升 授权（委托）书 卸货承揽人 劳埃德保险公司代理人; 劳埃德船级社代理人 拉美共同市 场 (船舶)满载吃水 拉美自由贸 易协会(联盟) 局域网 （WANs 广域网） 子母船；载驳船
Lat. = Latin Lat. = latit ude
拉丁 纬度 （longi tude 经度）
导航的, 主要的 轻载重吨 长途电话 总（分类）帐
1
led. Fo.; L.F. = ledge r folio leg. = Legal L4L Lot-for-Lot LEL = lower explo sive limit LFL = lower flamm able limit L/G = loss and gain (= L & G)；／ lette rof guara ntee l.g.r. = lease hold groun drent lgt. = Long ton;long tons L/H = lette rof hypot hecat ion LH = LOWER HOLD L/I＝Letter of indem nity LIBOR = Londo n Inter bank Offer ed Rate LIFO = last in - first out L.I.P.; LIP = life insur ance polic y liq. = Liqui d lkge = leaka ge lkge & bkge; Lkg/Bkg = leaka ge and break age L/L = LOADING LIST LLA = Long Length Addit ional LLDPE = Liner Low Densi ty Polye thyle ne Lloyd ’s = The corp. of Lloyd ’s LMDPE = Linear medium-density polyethylene LME = Londo n Metal Excha nge LNG = liqui fied natur al gas LOA = LENGTH OVER ALL load = loadi ng LOADREADY = READY FOR LOADING; READY TO LOAD LO/LO = lift on, lift off loc. = Local ;locat ion LOI = letter of intent
消费日益升级
BETTER COMMUNICATION ｜ GREATER VALUE Consumption upgrade? Standards have know-hows.消费日益升级？标准来助力BETTER COMMUNICATION ｜ GREATER VALUEBy Jin Yingguo 金英果SAC released the “special action plan for consumer product national standards (2019)” on June 4 to reinforce the construction of standards system in the field of consumer products and promote the improvement of their standards and quality. This action is also a strong echo of the Plan for the Improvement of Consumer Product Standards and Quality (2016-2020), a practical measure adopted three years ago with the aim to adapt to China’s consumption upgrade. Where is it headed now?China’s e-commerce platforms have achieved record sales during the mid-year “618” online shopping festival running from June 1 to 18. The cumulative value of delivered orders this year witnessed a 37 percent increase from last year’s festival sales.Sales of home appliances surpassed RMB 800 million in just three minutes and 47 seconds, while air conditioners worth more than RMB 100 million were sold in just 15 seconds. More than 50,000 smart phones were sold in the first three minutes of the event. The sales of beauty care products, eye cream, lipsticks, perfume, and baby and maternal products also rose massively, according to the data of Tmall, a widely known Chinese website for business-to-consumer online retail. All those figures show a consumption upgrade trend in China.Early in May, sales volume of daily consumer commodities grew over 10 percent, and medium- and high-end products like cosmetics and telecommunications equipment also contributed more to economic growth, says National Bureau of Statistics of China. It is reported that consumption expenditure contributed 76.2 percent to China’s GDP growth in 2018, an increase of 18.6 percent compared with the previous year. Consumption adds stronger impetus to economic growth in China.Policy response to consumption upgradeThe consumption of daily commodities is greatly impacted by product quality and price-performance ratio, so supply quality shall be improved to stimulate consumption demand, which is also conducive to the transition from “Made in China” to “Created in China”, from high-speed to high-quality, and from Chinese Product to Chinese Brand, pointed out President Xi Jinping, underlining the role of product quality in economic growth.Premier Li Keqiang reiterated the importance of consumer product standard and quality, requiring that we shall raise the level of standardization to promote the improvement of consumer product quality while keeping in line with international advanced standards. Only then can we boost the public confidence in the quality of domestic products and earn their recognition for product brand, and can consumption play its part in economic development and industrial transformation.As consumption continues to expand and upgrade, special measures have been taken in response to growing demands for higher product quality. SAC released the “special action plan for consumer product national standards (2019)” on June 4, which will launch 105 national standard projects for consumer products including 49 new standard development projects and 56 standard revision projects, to push the implementation of the Plan a practical step forward.The Plan (2016-2020) proposed in a State Council executive meeting on Autumn 24, 2016 is regarded as the key to advancing “Made in China 2025” strategic plan, ushering “Made in China” to medium- and high-ends, and strengthening the foundation for industrial development, since advanced standards have the potential to lead the improvement of consumer product quality anddrive the upgrade of equipment manufacturing industry.BETTER COMMUNICATION ｜ GREATER VALUEStandards play its partThe number of national standards and registered sector standards on consumer product has amounted to nearly 6,000 in mid-2016. Over 80 percent of such standards on home appliances, textiles and garment, furniture, toys and shoes have been harmonized with international standards. However, consumer product standard and quality were still unable to meet people’s growing consumption demand, which was accompanied with the inappropriate structure of supply chain, less competitive brand market, consumption environment demanding improvement and consumption confidence awaiting a lift. Under these circumstances, the Plan was approved and issued. Its goal is to achieve a balance between standards supply and demand in the field, grow close to the international advanced level in terms of consumer product quality in key areas, maintain constantly progressive inherent impetus for enterprise quality development, and largely raise the brand value of renowned consumer product.To this end, the Plan specifies eight major tasks for the next five years:· Reform the standards supply system and establish a new standards system with coordinated development of government-driven and market driven standards;· Optimize the structure of standards supply chain, so as to meet the demand of consumption upgrade;· Allocate the main responsibilit y forquality to enterprises and boost their intrinsicmotivation for quality improvement;· Strengthen the industrial infrastructure forconsumer products and improve the innovationcapability of quality technology;· Intensify brand construction and improvethe popularity and reputation of consumerproducts;· Improve market environment, stimulatemarket vitalit y and unlock consumptionpotential;· Innovate the regulation mode for qualityand safety of consumer products;· Implement the strategy of high-qualityforeign commerce import and export to improvethe quality of imported and exported consumerproducts.Impressive results have been achieved after three years of collaborative efforts of government, industries and standardization community. For instance, a new standards system is established and the legality of sector standards developed by social organizations is identified in the revised Standardization Law of China coming into force on January 1, 2018, to increase the effective supply of standards and meet the market demands. To ensure consumer product quality and safety, SAMR issued the guideline on the adoption of an innovativeregulation mode characterized by random selection of inspection objects and inspectors in all aspects of market regulation earlier this year. Some innovative projects put forward in the Plan strides smoothly forward, such as the self-declaration disclosure of sector and enterprise standards and the Enterprise Standard Forerunner Project. In March 2019, SAMR published a series of concrete results achieved since the implementation of the Plan in 2016, which will be showcased in details in the next pages.Standards have a bigger role to play, as the market needs for high-quality consumer product continue to expand. Besides, the government constantly builds up policy support for consumer product upgrade, along with the increasing importance of consumption in economic growth. For example, the National Development and Reform Commission of China released the action plan on promoting the upgrade of key consumer products and facilitating resource recycling on June 3, focusing on automobiles, home appliances and consumer electronics. There emerge more urgent needs for improving consumer product standard and quality.The next two years will be critical to the accomplishment of the Plan. Let’s keep up the momentum and make a difference!。
consumer demands and trends on food processing.
467Vol. 3, No. 4, October–December 1997Emerging Infectious DiseasesFresh, Preservative-Free Foods That Promote HealthFood industry marketers perceive that consumers want foods that are convenient; fresh (less-processed and less-packaged); all natural—with no preservatives (a so-called “clean label”);without a perceived negative (i.e., foods without high fat, high salt, and high sugar); and healthy.The industry perception is that consumers want foods that not only cause no harm but also remedy ailments from heart disease, osteoporosis, and fatigue to memory loss. Categories of foods that promote health are fortified foods, performance-enhancing food additives, probiotics, and prebiotics.Food fortification is an old process. Milk (with vitamins A and D), bread (with iron and niacin),or salt (with iodine) have long been fortified to replace nutrients thought to be lost during processing. Newer foods fortified with nutrients needed by the body to stave off the progression of diseases associated with aging or enhance physical performance attract the consumer’s attention and sell well in today’s marketplace.For example, marketers are promoting all sorts of foods fortified with calcium to women concerned about osteoporosis. Performance-enhancing foods are popular. Such foods range from beverages to replace electrolytes and prolong physical endur-ance to amino acids and fatty acids to improve alertness and memory. Probiotics and prebiotics are two paths to the same result. Researchstudies suggest that a desirable intestinal microflora causes the host to be less susceptible to intestinal pathogens. Probiotics create this desirable state by incorporating the microorgan-ism directly into the food, either as a stable culture or as part of food fermentation. This process is costly, and the microorganisms often do not survive well in the food. Thus, manufacturers must add 10 to 100 times the needed number of microorganisms to account for a loss of viability during the product’s normal shelf life. Prebiotics overcomes the limitations of probiotics by adding specific nutrients, usually a particular carbohy-drate, to the food. When ingested as part of the diet, these specific nutrients “select” for a beneficial microflora in the intestinal tract.Food Processing and Food Product DevelopmentThe consumer’s quest for health is having a great impact on the food processor. Compared with the marketplace of 25 years ago, today’s marketplace has more perishable products,including fruits and vegetables, and more innovative packaging. In addition, consumer aversion to traditional chemical preservatives has left food processors with less flexibility in choosing preservation methods. To find a technologic edge in the marketplace, food processors are exploring new processing and preservation technologies. Some of these tech-nologies include ohmic heating, high-pressure,pulsed electric field, bright light, and aseptic processing. Ohmic heating involves passing an electric current through the food to create heat due to electrical resistance within the food. WithThe Impact of Consumer Demands andTrends on Food ProcessingDon L. ZinkNestlé USA, Inc., Glendale, California, USAAddress for correspondence: Don L. Zink, Nestlé USA, Inc.800 N. Brand Blvd., Glendale, CA 91203, USA; fax: 818-549-6908; e-mail: donald.zink@.In the United States, consumer demand for new foods and changes in eating habits and food safety risks are affecting the food processing industry. The population is becoming older on average; moreover, consumers want fresh and minimally processed foods without synthetic chemical preservatives. To address the need for safer food and compete for consumer acceptance, manufacturers are exploring new food processing and preservation methods.ohmic heating, food particles heat at the same rate as the carrier medium or sauce. Ohmic heating can enhance food quality by limiting heat damage to the sauce and food particles. High-pressure processing uses very high pressure, often thousands of atmospheres, to pasteurize foods without heat. This technology is ideal for heat-sensitive foods, but some enzymes are difficult to inactivate with high-pressure process-ing. Pulsed electric field processing uses a very strong pulsed electric current to disrupt microbial cells and pasteurize foods with little or no heating. Bright light processing uses an intense white light to kill bacteria on the surface of foods; this light does not penetrate deeply into foods and can only be used for surface pasteurization.Aseptic processing dates back to at least the mid-1940s but has yet to realize its full potential. The most widely used of these new technologies, aseptic processing involves sterilizing a food product in a continuous process through a heat exchanger and then filling that food in an aseptic filler. The aseptic filler is a highly specialized piece of equipment designed to sterilize the packaging material, fill the sterile product into its container in a sterile environment, and then seal the package.Food processors have also explored novel food preservation systems. An ideal food preservative would come from a natural source and preserve food without being labeled a synthetic chemical preservative. Such preservatives include bacte-riocins, dimethyl dicarbonate (Velcorin), com-petitive microbial inhibition, controlled and modified atmospheres, and irradiation. Bacterio-cins are not new; however, like nisin, they are now being used to extend shelf life and enhance the safety of a variety of food products. The use of bacteriocins is likely to be expanded in the future. Dimethyl dicarbonate, a relatively new preserva-tive used in beverages such as wine, tea, and juices, is particularly effective in preventing spoilage caused by yeasts. Competitive microbial inhibition relies on the fact that many harmless bacteria, notably lactic acid bacteria, can inhibit the growth of both spoilage bacteria and pathogens. Inhibitory strains of lactic acid bacteria can be selected for use in dairy cultures or be added to refrigerated foods to extend shelf life and enhance safety. Modified and controlled atmosphere packaging are already widely used by the food industry. They have the potential foreven wider use, particularly with fresh fruits and vegetables sold at retail. These methods rely on inhibiting microbial growth by excluding oxygen or by inhibitory concentrations of carbon dioxide.Carefully selected gas mixtures can also delay the ripening of certain fruits and vegetables and extend the shelf life of fresh meats. Finally, irradiation, also not a new technology, is poised for widespread use to enhance the safety and shelf life of many foods. With proper controls, irradiation could be a valuable means of reducing Salmonella contamination of poultry and Es-cherichia coli O157:H7 contamination of ground beef.A Scientist’s View of Consumer TrendsOne of the most obvious consumer trends is a dramatic increase in the consumption of fresh foods, particularly fruits and vegetables. This increase is the result of the well-publicized value of a high-fiber diet and betacarotenes as an aid in preventing colon cancer. The number of meals eaten away from home has increased dramati-cally. The trend toward dining outside the home is likely rooted in lifestyle changes such as households with two working parents. The number of home-delivered meals, the ultimate convenience food, has also increased, even though the most popular foods consumed today (pizza and hamburgers) are generally the same as those of 20 years ago. This indicates that the types of foods consumed do not change rapidly, but the way these foods are consumed has changed. Finally, the population is getting older on average. Aging may not be a consumer trend, but it has a profound effect on food safety considerations. An older population means a more susceptible population.New food processing and preservation technologies and wider applications of older technologies have, for the most part, had little impact on most processed foods. Adoption of new technologies will likely continue at a slow pace.Consumers consistently buy foods on the basis of value and taste, not processing technology.Technologies that add value will be the first to gain consumer acceptance. The demand for convenience foods will probably increase. De-mands on our time are increasing, and we have less time to spend on food preparation, and more meals will be eaten away from home, in part because of convenience but also because of a trend for new tastes and variety in the diet.468Emerging Infectious Diseases Vol. 3, No. 4, October–December 1997Finally, the trend toward foods that claim to enhance performance, rooted in an aging population’s need for better health during longer life-spans, will continue. With increased demand,the pressure on the food industry for better processing and preservation methods will also increase and may result in safer food.469Vol. 3, No. 4, October–December 1997Emerging Infectious Diseases。
越来越多的人以外卖为生的现象英语作文
越来越多的人以外卖为生的现象英语作文全文共3篇示例，供读者参考篇1The Rise of the Food Delivery PeopleHave you ever ordered food from a place like McDonald's or Pizza Hut and had it delivered right to your doorstep? I'm sure most of you have! Food delivery services have become super popular nowadays. And you know what's even crazier? There are more and more people whose full-time job is to deliver food for companies like UberEats, GrubHub, and DoorDash!When I was younger, I thought all delivery people worked for the restaurants themselves. Like the guy who brings your pizza from Pizza Hut? I assumed he was a Pizza Hut employee. But that's not always the case anymore! Lots of these delivery workers don't actually work for the restaurants. Instead, they work for separate delivery companies that partner with tons of different restaurants.My dad explained it to me like this: restaurants don't have to hire their own delivery staff anymore. They can just work with companies like UberEats, and those companies hire the deliverypeople. The delivery companies have special apps that let you order food from all sorts of places. Then, their drivers pick up the food and bring it right to your house!At first, I thought this was a strange way to make a living. Driving around all day, just dropping off food? That didn't seem like a real job to me. But then my dad told me how much some of these drivers can make, and I was shocked! He said the busiest delivery people in big cities can make over 1000 per week if they work a lot of hours. That's more than some teachers and nurses make!From what I understand, it works like this: every time a delivery person picks up an order from a restaurant and drops it off at someone's house, they get paid a small fee—usually between 2 and 6. They also get to keep any tips that the customers give them through the app. While a single delivery fee doesn't seem like much, it can really start to add up if you do delivery after delivery all day long.My dad knows a guy named Jose who does UberEats deliveries full-time. Jose says on a typical day, he might do anywhere from 20 to 30 deliveries between lunch and dinner rushes. That means he could be making 60-100 or more just indelivery fees, plus all his tips on top of that! And he gets to be his own boss and make his own schedule, which is pretty cool.Of course, it's not all sunshine and rainbows. Jose has told my dad about some of the downsides too. He has to pay for his own gas, car maintenance, and insurance out of his earnings. He also doesn't get any benefits like health insurance or paid time off since he's considered an independent contractor, not an employee. And then there are the risks that come with driving around a lot—maybe getting into an accident, or even getting robbed or hurt when making deliveries in rough neighborhoods.Still, for a lot of people, the flexibility and money-making potential must make food delivery jobs pretty appealing. Just look around your neighborhood—I bet you see UberEats or DoorDash folks hustling all over the place these days!Personally, I can't wait until I'm old enough to get my driver's license. Making 1000 a week just for delivering food sounds like a pretty sweet gig to me! Although my parents will probably make me get an "actual" job first before trying something like that. We'll see...In any case, the rise of these food delivery workers is a fascinating trend that you're sure to notice more and more. Who knows, maybe someday having a job as a delivery driver will bejust as common as working at a restaurant or grocery store! The world is changing rapidly, and jobs like these that didn't really exist 10-15 years ago are suddenly becoming a major part of the economy.As for me, I'm just excited about all the food options I have at my fingertips thanks to these delivery people. McDonald's, Chipotle, my favorite Indian restaurant—I can get it all brought straight to my house with the push of a button! Being a kid in 2023 is pretty awesome that way. Although I do kind of miss the good old days of asking my parents to pick up a pizza on their way home from work...篇2The Rise of the Food Delivery WorkersHave you ever ordered food to be delivered to your home? Maybe it was a piping hot pizza, a juicy burger, or tasty Chinese takeout. Chances are, you have experienced the convenience of food delivery at some point. Well, these days more and more people are actually making their living by delivering food to homes and businesses. It's become a really big deal!You've probably noticed folks zipping around your neighborhood on scooters, bicycles, or even driving cars,carrying those familiar insulated bags from restaurants. Those are the food delivery workers, and their numbers seem to be growing by the day! Everywhere you look, there are people hustling to get someone's lunch, dinner, or late-night snack to them as quickly as possible.So why is this happening? Why are so many people deciding to make a job out of bringing food to people's doorsteps? Well, there are a few key reasons this occupation has exploded in recent years.First off, our modern lifestyles are incredibly busy these days. Parents are working long hours at their jobs, kids have activities like sports and music lessons in the evenings, and sometimes it's just too chaotic to prepare a home-cooked meal. That's where food delivery comes in so handy! With just a few taps on a smartphone app, you can have your favorite restaurant meal brought right to you. No need to spend time cooking or even leaving the house to go pick it up. Easy peasy!Another factor is that technology has made it simpler than ever before to order delivery. Those handy apps I mentioned connect customers to a huge variety of restaurants with delivery options. You can browse menus, pay digitally, and track your order all from your phone or computer. For the delivery workers,there are services they can sign up for that let them easily be matched with orders that need to be picked up and dropped off. Using mapping technology and logistics, these app companies efficiently coordinate a whole fleet of delivery contractors.People are also looking for ways to make extra money these days, especially with flexible schedules that allow them to choose their own hours. Delivering food can be a part-time gig to supplement someone's regular job and paycheck. Or it can be a main source of income where workers can settle into their own routine of choosing when and how much they want to work each week. Having that level of flexibility is very appealing to a lot of people.Of course, with the rise of this job there are some challenges too. One issue is the fact that cities and towns weren't really designed to have so many delivery workers constantly circulating throughout neighborhoods at all hours. There has been some chaos and concerns about safety with all of these drivers, bicyclists, and scooter riders swarming the streets. Lawmakers are having to figure out new rules and regulations to keep things safe and under control.There are also debates around the pay and workers' rights for delivery people. Since most of them are classified asindependent contractors rather than employees, they don't get the same benefits or protections as regular employees. Some make decent money, while others struggle with low pay after factoring in expenses like gas, insurance, and vehicle maintenance. It's a controversial arena that is still being worked out.Despite those hurdles, the food delivery work force appears here to stay and only continues growing. Maybe by the time I'm an adult, ordering delivery will be the norm rather than the exception. Just about everyone's food could be brought to them by an army of drivers, cyclists, and scooter riders! The world of convenient food logistics keeps evolving.For now, next time you hear a knock at the door and smell those delightful food aromas wafting in, take a moment to think about the person who brought your meal to you. They are part of one of the fastest growing labor forces in our economy. A whole new breed of mobile workers dedicated to getting you whatever food your heart (and stomach) desires as quickly as possible. Pretty cool when you think about it!So that's the scoop on all those food delivery people you see swarming around these days. A combination of busy lifestyles, technology, and flexible earnings opportunities has created abooming industry of folks making their living by bringing our meals right to us. I bet even more of my classmates will end up having this as a job someday! It's definitely a sign of the modern times we live in: convenient,快速的, 随时随地的食品交付不靠伙伴。
1970到1990的快餐消费英语作文
1970到1990的快餐消费英语作文The Rise of Fast Food Consumption: A Reflection on the 1970s to 1990sThe period from 1970 to 1990 marked a significant shift in the way people consumed food, with the rapid growth of the fast food industry. During this time, the convenience and affordability of fast food options became increasingly appealing to consumers, leading to a surge in its popularity and widespread adoption. This essay will explore the factors that contributed to the rise of fast food consumption and the societal impacts it had during this pivotal era.One of the primary drivers of the fast food boom was the changing lifestyle and demographics of the population. As more women entered the workforce, the traditional home-cooked meal became less practical for many families. The demand for quick and easy meal options grew, and fast food chains were able to capitalize on this need. The rise of the two-income household, coupled with the increasing number of single-parent families, created a market that was eager for the convenience and time-saving benefits of fast food.Furthermore, the urban sprawl and the development of suburbancommunities during this period played a crucial role in the expansion of the fast food industry. As people commuted longer distances for work and lived farther from the city center, the accessibility and convenience of fast food restaurants became increasingly appealing. Consumers could easily stop by a drive-thru or a fast food establishment on their way to or from work, satisfying their hunger without the need to prepare a meal at home.The affordability of fast food also contributed to its widespread adoption. As the cost of living rose, many consumers sought out more budget-friendly meal options. Fast food chains were able to offer relatively inexpensive meals, making them an attractive choice for families and individuals on a tight budget. This accessibility to affordable sustenance played a significant role in the rapid growth of the fast food industry during this period.In addition to the practical and economic factors, the marketing strategies employed by fast food companies also played a pivotal role in shaping consumer behavior. Aggressive advertising campaigns, targeting both children and adults, effectively promoted the idea of fast food as a convenient, desirable, and even aspirational lifestyle choice. The introduction of iconic mascots, such as Ronald McDonald, and the use of catchy slogans and jingles, cemented the presence of fast food brands in the public consciousness.The widespread adoption of fast food during the 1970s to 1990s had significant societal impacts. The convenience and accessibility of these establishments led to a decrease in the time and effort devoted to meal preparation, which in turn affected the social dynamics of family mealtimes. The traditional sit-down dinner, where families would gather and engage in conversation, was gradually replaced by the quick and often solitary experience of grabbing a meal on the go.Moreover, the rise of fast food consumption contributed to shifts in dietary patterns and health concerns. The typically high-calorie, high-fat, and high-sodium content of fast food items led to an increase in obesity rates and other diet-related health problems, such as heart disease and diabetes. This trend sparked growing concerns about the long-term health implications of the fast food-centric diet, prompting discussions and initiatives around healthier food options and nutritional education.The environmental impact of the fast food industry also came under scrutiny during this period. The reliance on disposable packaging, the use of energy-intensive cooking methods, and the transportation of ingredients over long distances all contributed to the industry's significant carbon footprint. As environmental awareness grew, the sustainability of the fast food model was increasingly questioned, leading to calls for more eco-friendly practices and the developmentof alternative food systems.In conclusion, the rise of fast food consumption during the 1970s to 1990s was a complex phenomenon driven by a combination of societal, economic, and marketing factors. While the convenience and affordability of fast food initially appealed to consumers, the long-term impacts on public health, social dynamics, and the environment have continued to be a subject of ongoing debate and reflection. As we look back on this era, it is essential to understand the lasting implications of the fast food boom and to consider how we can shape a more sustainable and balanced approach to food consumption in the future.。
Online Food Shopping
Online food shopping has become increasingly popular in recent years, with more and more people choosing to purchase groceries and other food items via the internet. This trend has been driven by the convenience and accessibility of online shopping, as well as thewide variety of options available to consumers.One of the key advantages of online food shopping is the convenience it offers. Instead of having to physically visit a grocery store, customers can simply browse through a website or app, add items to their virtual cart, and have them delivered directly to their doorstep. This saves time and effort, making it a popular choice for busy individuals and families.In addition to convenience, online food shopping also provides awide range of options for consumers. Many online retailers offer a diverse selection of products, including organic and specialty items that may not be readily available in traditional brick-and-mortar stores. This allows shoppers to explore new and unique food products from the comfort of their own homes.Furthermore, online food shopping can also be more cost-effectivefor consumers. With the ability to easily compare prices and take advantage of digital coupons and discounts, shoppers can often find better deals and save money on their grocery purchases.However, there are also some potential drawbacks to online food shopping. Some consumers may be concerned about the quality and freshness of the food items they receive, as well as the potentialfor items to be damaged during delivery. Additionally, there may be delivery fees or minimum order requirements that could impact the overall cost of online food shopping.Overall, online food shopping offers a convenient and diverse option for consumers to purchase groceries and food items. As technology continues to advance, it is likely that online food shopping will become even more prevalent in the future, providing an alternativeto traditional in-store grocery shopping.。
功能饮料消费市场状况分析(英文)
1.Consumption market analysis of energy beverage
Average consumption The acquaintance of energy drink Drinking rate of energy drinks Purchase reason for energy drink Diagram
②The acquaintance of energy drink
City dwellers’ acquaintance of energy drink is general on the low side. According to the survey, city dwellers from different city have great different acquaintance. To energy drinks. Beijing residents" acquaintance is in the highest level with 85%;Jinan、Shanghai、Wuhan residents’ acquaintance level is lower. About 44% residents don’t know the energy drinks .(remarks: residents refer to consumers who buy soft drinks on their own initiative).Although it seems energy drinks advertisement emerges in an endless stream, many new products appear, but consumer’ acquaintance is not enough. Less of awareness is an important factor that influences the development of energy drinks. How to guide consumers know more about energy drinks, improve the acceptability of energy drinks market, this is one of the problems that need urgebrand &present deveopment of energy beverage indurstry.
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DEPARTMENT OF ECONOMICSUNIVERSITY OF CYPRUSAGE EFFECTS ON CONSUMER DEMAND:AN ADDITIVE PARTIALLY LINEAR REGRESSION MODEL Panayiota Lyssiotou,Panos Passhardes andThanasis StengosDiscussion Paper 99-06P.O. Box 20537, 1678 Nicosia, CYPRUS Tel.: ++357-2-892101, Fax: ++357-2-750310Web site: http://www.econ.ucy.ac.cyAge e¤ects on Consumer Demand: An Additive Partially Linear Regression ModelPanayiota LyssiotouUniversity of Cyprus,POBox537,Nicosia,Cyprus(p.lyssiotou@ucy.ac.cy)Panos PashardesUniversity of Cyprus,POBox537,Nicosia,Cyprus(p.pashardes@ucy.ac.cy)Thanasis Stengos1University of Guelph,Guelph,Ontario,Canada N1G2W1(thanasis@css.uoguelph.ca)February19991We would like to thank the University of Cyprus for…nancial support and the Central Statistical O¢ce for making available the UK Family Expenditure Survey data through the ESRC Data Archive.We are solely responsible for the interpretation of the data and all errors.AbstractAn additive partially linear regression model is used to estimate nonparametrically the e¤ects of total expenditure and age in the context of Engel curves and investigate the speci…cation and welfare interpretation of the age e¤ects in parametric models of con-sumer behavior.Empirical analysis based on data drawn from the UK Family Expen-diture Survey shows that modelling of the e¤ects of age requires a more sophisticated approach than that generally adopted in parametric demand analysis.It also shows that failing to adequately capture these e¤ects can have misleading welfare implications.JEL Classi…cation:C14,D12Keywords:nonparametric methods,Engel curves,relative equivalence scales.Age E¤ects on Consumer Demand:An Additive Partially Linear Regression Model1IntroductionThe bene…ts of using nonparametric methods in empirical demand analysis have been recently highlighted by Blundell and Duncan(1997),Gozalo(1997),Donald(1997), Pendakur(1999)and Lyssiotou,Pashardes and Stengos(1999)among others.These studies are mostly concerned with…nding appropriate ways of modelling the e¤ect of expenditure on consumer demand.In this paper we concentrate mainly on the age e¤ects and our approach also di¤ers from previous empirical investigations insofar as we use an additive Partially Linear Regression model to do so.The additive PLR model can be seen as a way of tackling the‘curse of dimensionality’problem,one of the most important weaknesses of nonparametric estimation methods. In recent papers Linton and Nielsen(1995),Fan,Härdle and Mammen(1996)and Fan and Li(1996)all employ marginal integration as a way of obtaining estimates of the components of the additive regression model.Linton and Nielsen’s(1995)paper deals with a simple additive model with two components,whereas Fan,Härdle and Mammen (1996)and Fan and Li(1996)extend the regression function to allow for a more general partially linear formulation.In this paper we follow the treatment of Fan and Li(1996) that results in estimates with better…nite sample properties.The nonparametric investigation of how expenditure and age a¤ect consumer de-mands is important because these two variables are generally found to have pronounced e¤ects on consumer behavior(Blundell,Pashardes and Weber1993and Gozalo1997). Furthermore,expenditure and age are continuous variables and their parameterization can be associated with a wider margin of misspeci…cation error than other variables entering demand systems as dummies.The importance of using an additive PLR model relates to the fact that in the context of this model the expenditure and age e¤ectson consumer can both be investigated nonparametrically at the same time.This can improve e¢ciency and reduce the risk of obtaining misleading conclusions about the e¤ects of one of these variables because the e¤ects of the other are misspeci…ed.We investigate empirically the points raised above using individual household data drawn from the UK Family Expenditure Survey and use the results obtained from nonparametric analysis to examine the modelling of age and expenditure e¤ects in a parametric system of Engel curves.Furthermore,we examine the welfare implications of alternative parameterization of the age e¤ects using the concept of the relative equiv-alence scale,de…ned as the ratio of the true cost of living indices of two households with di¤erent demographic characteristics(Blundell and Lewbel1991).Generally this scale is used for calculating di¤erences in the e¤ects of in‡ation on the cost of living of households with and without children(e.g.Dickens,Fry and Pashardes1993).In this paper we use the relative equivalence scale to compare the e¤ects of in‡ation on the cost of living of households with di¤erences in the age of head.The structure of the paper is as follows.Section2describes the additive PLR model and reports empirical results obtained from its application to individual household to data.Section3investigates the implications of the nonparametric results for the parametric speci…cation and welfare interpretation of age e¤ects in a system of Engel curves.Section4concludes the paper.2An additive partially linear regression model Consider the following additive PLR model with two regressors:w i=®+g1(X1i)+g2(X2i)+u i;i=1;:::;n;(1) where f w i;X1i;X2i g n i=1are independently and identically distributed(i.i.d.)random variables,E(u i j X1i;X2i)=0;®is an unknown parameter,g1(:)and g2(:)are unknownunivariate functions that obey the identi…ability condition that E(g1(X1))=0andE(g2(X2))=0:As shown by Stone(1985,1986)the additive components g s(:)(s=1;2)in(1)canbe consistently estimated at the same rate as a fully nonparametric regression with onlyone regressor.This can be done by employing marginal integration as in Linton andNielsen(1995),Fan,Härdle and Mammen(1996)and Fan and Li(1996).In this paperwe follow the treatment of Fan and Li(1996)that results in estimates with better…nitesample properties.The idea behind marginal integration in the context of equation(1)can be described as follows.Let E(w j X1=x1;X2=x2)=a(x1;x2):One can estimate a(x1;x2)by a nonpara-metric local smoother,say b a(x1;x2);and then obtain an estimator of f g1(x1)+®g byintegrating b a(x1;x2)over z2;i.e.,e m1(x1)=n¡1P n j=1b a(x1;X2j):Since E(g1(X1))=0; we can obtain the estimator of g1(x1)by subtracting the sample mean of e m1(:)frome m1(x1);i.e.e g1(x1)=e m1(x1)¡n¡1P n i=1e m1(X1i):Similarly,we can obtain an estimator for g2(x2):Equation(1)can be extended to allow for an additive linear component.In thatcase we havew i=®+Z T i¯+g1(X1i)+g2(X2i)+u i;i=1;:::;n;(2) where Z i is a variable(discrete or continuous)of dimension q;¯is a q£1vector ofp n¡consistent parameters and®is a scalar parameter as before.We can obtain aestimator of¯using Robinson’s(1988)approach.Let us denote such an estimator by b¯:Equation(2)can be then written asw i¡Z T i b¯=®+g1(X1i)+g2(X2i)+u i+Z T i(¯¡b¯);i=1;:::;n;(3) where u i;+Z T i(¯¡b¯)is the new composite error term.In a similar fashion as with equation(1)we can apply marginal integration to equation(2)to obtain estimates of g1(x1)and g2(x2):We estimate the above model for a system of Engel curves consisting of six categories of non-durable commodities:food,alcohol,fuel,clothing,other goods and services.1. The data used are drawn from the1980UK Family Expenditure Survey(FES)and in-clude two-adult households whose head is under retirement age and not self-employed. For the nonparametric analysis in this section a random sample consisting of427obser-vations is selected from these data.Introducing the subscript h to denote households,the dependant variable w ih is de…ned as the share of the i th good in the budget of the h th household whereas,the regressors X1h and X2h are de…ned as the age of household head and the logarithm of the household budget,the two continuous variables normally included in demand systems estimated from individual household data.The vector Z h is de…ned to include a large number of dummy variables re‡ecting family composition,sex,employment and economic position of members,housing tenure and other household characteristics found elsewhere to have a signi…cant e¤ect on consumer behavior by studies using UK FES data(Blundell et.al.1993).2In the diagrams of Figure1the heavy continuous line shows the estimated age e¤ect on the budget shares of food,alcohol,fuel and clothing obtained from the additive PLR model(3).The light line shows the age e¤ect obtained from a semiparametric estima-tion where the logarithm of expenditure enters the budget shares nonparametrically, whereas age and other household characteristics enter parametrically.This semipara-metric speci…cation includes age and age square as explanatory variables as in other empirical studies mentioned above.Also in the diagrams of Figure1we report the 95%con…dence band(light discontinuous lines)corresponding to the nonparametric 1The assumption concerning durable goods is that they act as conditioning variables and this is modelled by including dummies for housing tenure,the size and value of the house,car ownership,the presence of smokers in the household etc.in the vector of household characteristics.2To capture possible interactions between the age of household head and the logarithm of household budget we have also included the product of these two variables among the Z vector.This product term was found to be signi…cant.estimates obtained from the additive PLR model.3Figure 1: Nonparametric age effectsThe di¤erence between the age e¤ects estimated from the additive PLR model and those estimated from the semiparametric model is striking.In three out of four goods presented in Figure1(alcohol,fuel and clothing)the Engel curves obtained from the two models go mostly in di¤erent directions so that the parametric estimates are within the95%con…dence band of the nonparametric ones only where the lines estimated from3The smoothing parameters in the graphs were chosen as c s xi n¡1=5;where s xiis the estimate of thestandard deviation of X i;i=1;2:The choice of c was done by cross-validation in a range between0.5 and2.the two models intersect!The most pronounced di¤erence occurs in the case of clothing where the nonparametric results suggest that age has a negative e¤ect on the budget share globally,whereas the parametric results suggest exactly the opposite.Even in the case of food where the di¤erences between the two models are not so pronounced,the parametric results are outside the95%con…dence band of the nonparametric estimates over a wide range of age variation(i.e.households with head between20-25and45-60 years old).3Age e¤ects in parametric demand analysisIn this section we investigate the modelling of age e¤ects in a parametric system of Engel curves in the light of the nonparametric results of the previous section.More speci…cally,the same categories of non-durable goods estimated nonparametrically in the previous section are estimated parametrically using the system of Engel curvesw ih=®i+P k¯ik Z hk+P sõis+P j¹ijs D jh!X s1h+P r¸ir X r2h(4) where the variables Z hk,X1h and X2h are as de…ned in the previous section.The choice of(4)re‡ects the fact that it is su¢ciently general to cover many of the popular Engel curves and demand systems estimated with individual household data,e.g.those of Working(1943),Deaton and Muellbauer(1980)and subsequent generalizations such as Blundell et.al.(1993)and Banks et al(1997).Moreover it can allow for the rather complex nonlinear age e¤ects on the budget shares,suggested by the results obtained from the additive PLR model in the previous section.More speci…cally,(4)can accommodate(i)a polynomial form,§sµis X s1h;to capture higher order age e¤ects and(ii)a dummy variable form,§s§j¹ijs D jh X s1h;to capture age e¤ects peculiar to certain household groups.Following initial investigation we found that the Quadratic Logarithmic version of(4),i.e.r=2;with up to cubic age e¤ects,s=3;and dummies to capture the behavior of households with heads under30was su¢ciently general to explain the age and log expenditure e¤ects on the budget shares in our sample.4In terms of the logarithmic ex-penditure e¤ects,this result is in agreement with the…ndings of most previous empirical studies in the literature,Lewbel(1991),Blundell et al(1993),Pashardes(1995),Banks et al(1997)and Lyssiotou et al(1999)among others.This,however,is not true for the age e¤ects in the sense that we…nd no empirical evidence in support of the hypothesis that these e¤ects are linear and quadratic,as reported in the aforementioned studies.This point is illustrated empirically by estimating the system of Engel curves w ih=®i+P k¯ik Z hk+3P s=1(µis+¹is D<30)X s1h+2P r=1¸ir X r2h;(5) where D<30=1for households with head under30and D<30=0otherwise.As in the previous sections six categories of non-durable commodities are considered(food, alcohol,fuel,clothing,other goods and services)and the data are drawn from the1980 UK FES.5The…rst pair of columns in Table1,under the heading‘full’,shows parameter estimates and t-ratios obtained from the estimation of(5)without any restrictions on the age e¤ects.The second pair of columns in Table1,under the heading‘quadratic’, shows parameter estimates and t-ratios obtained from(5)subject to the restrictions that there are no cubic age e¤ects(µi3=0;all i)and no dummy e¤ects for households with head under30(¹is=0;all i and s).As shown by in the last line of the second pair of columns in Table1this hypothesis implies15parameter restrictions and reduces 4The Quadratic Logarithmic demand system(Lewbel1991)itself comes from a general demandsystem of the form,w ih=P R r=1¸ri(p;z h)F r[y h¡a(p;z h)];the rank of which equals the rank of the n by R matrix of elements¸ri:Lewbel(1989)proved that utility maximization requires that the rank of demand systems in this form must be less than or equal to four and Gorman(1981)proved that when F r(:)=:r¡1,utility maximization requires that the rank of(4)must be less or equal to three,with ¸4i=·¸3i for some scalar·:5The observations used for the estimation of(5)correspond to households with two-adults and a head under retirement age and not self-employed,a total of2770observations.the2Log-Likelihood(2LL)statistic by154.Therefore,it fails decisively theÂ2-test at the5signi…cance level.Table 1: Parameter estimates for the age effectsNext we investigate the question whether one needs to augment the‘quadratic’model to include cubic age e¤ects and e¤ects for households with head under30or adding just one of these two types of e¤ects is su¢cient.To answer this question we impose on(4)the corresponding restrictions(i)µi3=0;all i;and(ii)¹is=0;all i and s,separately.The parameter estimates and standard errors obtained from these restrictions are reported in the third and fourth pair of columns in Table1(under the heading‘cubic’and‘dummies’,respectively)with the reduction in the2LL statistic appearing in the last line.On the basis of theÂ2-test none of the two sets of restrictions can be rejected at the5signi…cance level.Therefore,the data used in our empirical analysis suggest that either a model with up to cubic age e¤ects or a model with up to quadratic age e¤ects and dummies to capture the behavior of households with head under30is an adequate empirical speci…cation of the age e¤ects on consumer demands.In the remainder of this section we illustrate how welfare measures derived from observed consumer behavior can be a¤ected by the alternative parameterization of the age e¤ects de…ned by the‘full’,‘quadratic’,‘cubic’and‘dummies’models de…ned above. The welfare measure chosen for this illustration is the relative equivalence scale com-paring the e¤ects of a price change on the cost of living of households.Here we de…ne this scale for a price change from P0to P t and the cost of living comparison is between households in di¤erent age ing the subscript o to denote households in the reference age category,the relative equivalence scale isR ho(P t;P0)=C(P t;Z h;X1h;U h)=C(P0;Z h;X1h;U h)C(P t;Z h;X1o;U o)=C(P0;Z h;X1o;U o);(6)where C(P`;Z h;X1m;U m)represents the cost of reaching the utility level U m at prices P`by a household with head aged X1m;for`=1;0and m=h;o:Under the Quadratic Logarithmic model the cost function has the formlnC(P`;Z m;U m)=¯(P`;Z m;X1m)+¸1(P`)U h2`h;(7)where the¯(P`;Z m;X1m);¸1(P`)and¸2(P`)functions are homogeneous in prices.We assume that at base period prices there is a compensation for age di¤erences betweenhouseholds types are such that U h=U o:The logarithm of the relative equivalence scale showing the compensation for in‡ation required so as to maintain this utility parity in the new price regime islnR ho=[¯(P t;Z h;X1h)¡¯(P t;Z o;X1o)]+[¯(P0;Z o;X1o)¡(P0;Z h;X1h)](8)Assuming that¯(P`;Z m;X1m)has the usual translog form¯0+P i·®i+P k¯ik Z hk+3P s=1(µis+¹is D<30)X s1h+P n°in lnP`n¸lnP i` and setting P0i=0for the base period(6)can also be written aslnR ho=P i·P k¯ik(Z hk¡Z ok)+3P s=1(µis+¹is D<30)(X s1h¡X s1o)¸lnP it:(9) The diagram of Figure2reports the relative equivalence scales calculated with(8) using the parameter estimates obtained from the alternative parameterization of the age e¤ects described above.The relative equivalence scales obtained from using the parameter estimates of the‘full’model suggest that in the UK over the period1980-86 households with head over50experienced a cost of living increase of1.4%above the cost of living increase experienced by households with head under30.This…gure for the ‘quadratic’model was only0.4%,whereas for the‘dummies’and‘cubic’models1.0% and1.3%,respectively.Figure 2: Relative equivalence scales for age differences4ConclusionThis paper investigates the e¤ect of age and expenditure on consumer demand using an additive partially linear regression model where the e¤ects of both these variables are estimated nonparametrically.Empirical results obtained from the application of this model to UK data suggest that age has more complicated e¤ects than those generally assumed in empirical speci…cations of parametric demand systems.In particular,we have found that households with younger heads tend to behave di¤erently than other households and this is not adequately captured in a demand system where only linear and quadratic age e¤ects are included in the empirical speci…cation.In the case of our sample an adequate empirical demand system requires either cubic age e¤ects or dummies to capture di¤erences in the behavior of households with head at the lower end of the age distribution.The welfare implications of inadequately 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