经济增长的长期趋势

➢ 技术进步会增加劳动和资本的边际产品，从而提高工 人的实际工资，也有利于资本家。技术进步提高了生 产率，是生活水准提高的途径。
5. New Growth Theory: Inquire into Sources of Technological Progress In Neoclassical Model of economic growth, technological progress is exogenous. But NGT treats it endogenous.
------Technological progress is a produced factor ------The difference between rich countries and poor
countries can attributed to technological differences ------It is a public product ------Public policy is needed to protect intellectual
3. The Growth of Golden Rule
并非人均资本越高的稳定 状态就越好，存在着一 个最优的稳定状态
人均资本越高，折旧也越 高，为了维持这些资本 需要耗费更多的产出， 减少了当期消费
3.1 The golden rule
A saving rate such that
Max f（k）- sf（k） St. s f（k） -δk＝ 0
➢△k = s f（k） - (δ+n) k
Summary
1. In the long run, an economy reaches steady state, in which output, capital and labor all increase in the same rate so that output per capita remains unchanged.
property right.
Growth Theory and Reality 1. The Miracle of Japan and Germany 2. East Asian Miracle 3. The gap between the poor and the rich
4. The level of capital that maximizes steady-state consumption is called the Golden Rule level
5. An economy’s rate of population growth is another long-run determinant of the standard of living.
2. In the long run, the rate of saving determines the size of its capital stock and thus its level of production
3. The change in saving rate has a level effect on income per capita only, and saving by itself cannot generate persistent economic growth.
6. Technology progress is the main source of economic
More Implications
➢ 随着资本深化 (capital deepening)，劳动的边际产品增 加，资本的边际产品减少。因此工人实际收入增加，ቤተ መጻሕፍቲ ባይዱ而资本的收益下降。
➢ 如果不发生技术变化，经济增长和资本的深化将达到 稳定状态，此时资本深化停止，工人收入不再增加。
Starting with too little capital
4.Population and Growth
4.1 The Growth with Population Growth ➢The capital formation: sy ➢The leakage of capital: depreciation (δ) and
人均产量、投资与折旧
折旧，δk
人均产量，f（k） 投资
投资
k1* k2* 人均资本
The golden rule k satisfies: MPK = δ
3.2 A Numerical Example
3.3 The Transition to Golden Rule Steady State Starting with too much capital
dilution due to population growth (n) ➢△k = s f（k） - (δ+n) k
• Population and Growth
➢△k = s f（k） - (δ+n) k
4.2 The Effects of Population Growth Changes