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第十二章短期经济颠簸模型：总需求-总供给解析1.总需求曲线为何向右下方倾斜？答案要点：总需求会随着价格水平的提高而下降，也许随着价格水平的下降而提高。
这也就是价格水平变动所引起的财富效应（实质余额效应）。
因此，总需求曲线会向右下方倾斜。
2.财政政策对增加均衡公民收入收效较好的条件是什么？答案要点：从总供求模型来说，总供给曲线越平坦，即物价水平变动很小或几乎不变动，总需求曲线越陡直，即总需求对于价格不敏感，财政政策对增加均衡公民收入的收效就越好。
自然，经济中也必定有财政政策发挥作用的重要的详尽项目。
3.钱币政策对增加均衡公民收入收效较好的条件是什么？答案要点：从总供求模型来说，总供给曲线越陡直，即物价水平变动很大也不会影响总供给，总需求曲线越平坦，即总需求对于价格很敏感，钱币政策对增加均衡公民收入的收效就越好。
自然，经济中也必定有钱币政策能够发挥作用的企业投资的重要详尽项目。
4.以财政政策促进经济恢复或增加的限制性和副作用各是什么？答案要点：若是是以增加政府支出的财政政策恢复经济或促进经济增加，必定有好的项目，同时也不能够因此引起利率上涨。
若是没有这些条件，就会产生限制性和副作用：因利率上涨而以致原来可由社会进行的投资被放弃，即产生“挤出效应”，也许因缺乏合适的投资支出的对象，而无法达到目的。
若是以减税的财政政策恢复经济或促进经济增加，也有限制性，即，企业找不到能够盈利的投资项目，就不会因减税而增加投资，从而无法达到预定的目的。
5.以钱币政策促进经济恢复或增加的限制性和副作用各是什么？答案要点：一是受限于经济中可否存在可盈利的投资项目，二是扩大性钱币政策可能以致通货膨胀。
6.将财政政策和钱币政策配合使用的原由是什么？答案要点：能够互相填充单独使用钱币政策或财政政策时存在的限制性和弊端，防备或降低副作用。
Chapter 12: Answers to Questions and Problems1.a. The expected value of option 1 is()()()()()300100161200164500166200164100161=++++. The expected value of option 2 is ()()()()()11111801701,0001708030055555++++=. b. The variance of option 1 is()()()()().000,2530010016130020016430050016630020016430010016122222=−+−+−+−+−Similarly, the variance of option 2 is 124,120. The standard deviation of option 1 is 158.11. The standard deviation of option 2 is 352.31.c. Option 2 is the most risky.2.a. Risk loving.b. Risk averse.c. Risk neutral.3.a.$5. b.She will purchase, since your price is less than her reservation price. c.$6. d. She will continue to search, since the price exceeds her reservation price.4.a. ()().6$100.4$200$140Ep =+=.b. Set Ep = MC to get 140 = 1 + 4Q . Solve for Q to find your profit-maximizing output, Q = 34.75 units.c. Your expected profits are (Ep)Q – C(Q) = $140(34.75) – (34.75 +2(34.75)2)=$2,415.13.5.a. The expected value, which is $25.b. The maximum value, which is $50.6.a. With only two bidders, n = 2. The lowest possible valuation is L = $1,000, and your own valuation is v = $2,500. Thus, your optimal sealed bid is$2,500$1,000$2,500$1,7502v L b v n −−=−=−=. b. With ten bidders, n =10. The lowest possible valuation is L = $1,000, and your own valuation is v = $2,500. Thus, your optimal sealed bid is$2,500$1,000$2,500$2,35010v L b v n −−=−=−=. c. With one hundred bidders, n =100. The lowest possible valuation is L = $1,000, and your own valuation is v = $2,500. Thus, your optimal sealed bid is$2,500$1,000$2,500$2,485100v L b v n −−=−=−=.7.a. With 5 bidders, n = 5. The lowest possible valuation is L = $50,000, and your own valuation is v = $75,000. Thus, your optimal sealed bid is$75,000$50,000$75,000$70,0005v L b v n −−=−=−=. b. A Dutch auction is strategically equivalent to a first-price sealed bid auction (see part (a)). Thus, you should let the auctioneer continue to lower the price until it reaches $70,000, and then yell “Mine!”c. $75,000, since it is a dominant strategy to bid your true valuation in a second-price, sealed-bid auction.d. Remain active until the price exceeds $75,000; then drop out.8.a. Hidden actions lead to moral hazard; hidden characteristics lead to adverse selection.b. Incentive contracts can solve moral hazard problems; screening and sorting can solve adverse selection problems.9. Since this is a common value auction, bidders will not bid their own private estimates because doing so would lead to the winner’s curse. Thus, there will be an additional incentive for bidders to shade their bids below their estimated valuations. The English auction format provides bidders the most information (therefore allowing them to pool information to some extent), mitigating this problem. For this reason, the English auction would generate the highest expected revenues in this case.10.Your expected inverse demand is E(P) = .5(200,000 – 250Q ) + .5(400,000 – 250Q ) = 300,000 – 250Q. Therefore, your expected marginal revenue is E(MR) = 300,000 – 500Q . Your marginal cost is MC = $200,000. Setting E(MR) = MC yields300,000500200,000Q −=. Solving, Q = 200. The price you expect is thus E(P) = 300,000 – 250(200) = $250,000. Your profits are thus ($250,000 -$200,000)(200) - $110,000 = $9,890,000.11. One would expect higher premiums on credit life, thanks to adverse selection. Peoplewho cannot pass physicals will select toward this type of insurance, resulting in higher premiums. Furthermore, people who are healthy and can pass a physical will be unwilling to pay the higher premiums, thus exacerbating this effect.12. The expected benefit from an additional search are 0.05($110,000 - $60,000) = $2,500, while the cost of another search is $5,000. Therefore, make her an offer. 13. In the absence of "guaranteed issue," an insurance company could choose to insure only those employees with a very low risk structure. In this case they offer lower rates because they experience fewer claims. But this leaves those workers with greater risk factors without insurance. By requiring insurers to offer coverage to all employees, the insurance company must take on employees that are less healthy and a greater risk. Why the controversy? By insuring those with greater health risks, the expected number of claims rises, thus increasing the cost of coverage. The workers with existing health problems benefit at the expense of healthy workers, who pay higher prices with "guaranteed issue." If the price rises high enough and healthy workers are free to drop coverage, this can result in adverse selection: The only people willing to pay the higher premiums are those in poor health.14. Brownstown Steel has better information about its financial situation than does its lenders, and is attempting to use this information advantage to enhance its bargaining position. If lenders gained full information about the financial situation of Brownstown Steel Corp., they would be in a position to squeeze the maximum amount from Brownstown Steel without fear of pushing it into bankruptcy. Absent the information, lenders will be more generous, since taking too much would increase the risk that Brownstown Steel goes bankrupt.15. The 30-day warranty and 10-point inspection. This not only reduces buyer risk from being duped by a used car dealer, but provides a costly signal about the quality of the used cars sold. An unscrupulous dealer would find it costly to mimic this strategy. Recognizing both of these facts, rational buyers will be more willing to purchase cars from the dealer.16. Offer two plans for customers with more than $1 million in assets. One plan (perhaps called the “Free Trade” Account) has an annual maintenance fee of $10,000 good for up to 400 “free” transactions (computed as $10,000/$25) per year (each additional transaction is priced at $25 each). The other plan (perhaps called the “Free Service” Account) has no annual maintenance fee but charges $100 per transaction. Given these two options, investors will sort themselves into the plans based on their individual characteristics.17.With 5 other bidders, n = 6. The lowest possible valuation is L = $5,000, and your own valuation is v = $12,000. Thus, your optimal first-price, sealed-bid is$12,000$5,000$12,000$10,833.336v L b v n −−=−=−=.18. A risk-neutral Oracle’s bid of $7 billion is low since the expected value of the presentvalue of the stream of profits is $7.6 billion. The public bidding process described most resembles an independent, private value English auction (each company places a different probability assessment on the value of the company that depends onpotential realized synergies). SAP’s expected value of the present value of the stream of profits is $8.4 billion. Since this is greater than Oracle’s expected value, SAP will win the “auction” and acquire PeopleSoft. SAP will pay just over $7.6 billion for PeopleSoft.19.The expected value of aggregate ten-year profits of a McDonald’s franchise is ()()()75.4$1$25.5$50.10$25.=−++million. Similarly, the expected value of a Penn Station East Coast Subs’ franchise is ()()75.4$)30$(025.5$95.30$025.=−++million. The variance and standard deviation of owning a McDonald’s franchise is()()()1875.1575.4125.75.4550.75.41025.2222'=−−+−+−=s McDonald σand 8971.31875.152''===s McDonald s McDonald σσ, respectively. Similarly, the variance and standard deviation for Penn Station East Coast Subs’ is()()()1875.4675.430025.75.4595.75.430025.2222=−−+−+−=Penn σand7961.61875.462===Penn Penn σσ, respectively. Since the expected values are thesame we can compare the standard deviations to determine the most risky investment. Since s McDonald Penn 'σσ>there is more risk associated with a Penn Station East Coast Subs’ franchise.20. There are several things for a student to consider in deciding to enroll in a traditionalMBA program or an online MBA program. It is likely that students with a spouse and family may be more attracted to online MBA programs, since these individuals are value stability and have others relying on them for income. In contrast, traditional MBA programs are more likely to attract singles who are willing to bear theopportunity cost associated with this form of education. Thus, there is an adverse selection issue. The individual who selects the traditional MBA program is likely to have a stronger signaling value regarding underlying characteristics.21.Market collapse is likely since “outsiders” will be unwilling to participate in equity (or other) markets since they know “insiders” will only sell a stock when they know the price is too high. Similarly, insiders will only buy when the price of a stock is known to be low. This is a losing proposition for outsiders, who would rationally choose not to participate in the market. This is an example of a moral hazard and is one of the primary reasons the SEC exists.。
