【正文】 eir inhabitants.(2) The process whereby the real per capita ine of a country increases over a long period of time, subject to the stipulations that the number of people below an absolute poverty line does not increase and that the distribution of ine does not bee more unequal. (3) Economic development is a means to make mass people out of poverty. What development economics studies? DE studies the economic structure and behavior of the poor (less developed) countries (Lewis, 1984). Development Economics (DE) studies the economic transformation of developing countries (Debraj Ray, 1998). The major task of DE is to explore the possibilities of emancipation from poverty for developing economies (Yujiro Hayami, 2001). DE is about the big issues: how economies and societies grow and change (N. Stern, 2001). Backward ? underdevelopment ? less developed countries ? poor countries emergent countries ? developing economies.  研究?jī)?nèi)容（研究什么）(1) 理解現(xiàn)在世界各國(guó)發(fā)展的不平衡性。China’ rank of HDI in the world, 19702010 研究方法(1) 理論研究與經(jīng)驗(yàn)研究（theoretical and empirical approach） (2) 發(fā)展微觀經(jīng)濟(jì)學(xué)與發(fā)展宏觀經(jīng)濟(jì)學(xué)（development microeconomics and development macroeconomics）(3) 純粹的經(jīng)濟(jì)分析還是多學(xué)科研究 歷史演變(1) 古典經(jīng)濟(jì)學(xué)是當(dāng)時(shí)的發(fā)展經(jīng)濟(jì)學(xué)(2) 在20世紀(jì)40年代后期，現(xiàn)代發(fā)展經(jīng)濟(jì)學(xué)形成。s external economies and big push,This theory is an investment theory which stresses the conditions of takeoff. The argumentation is quite similar to the balanced growth theory but emphasis is put on the need for a big push. The investments should be of a relatively high minimum in order to reap the benefits of external economies. Only investments in big plexes will result in social benefits exceeding social costs. High priority is given to infrastructural development and industry, and this emphasis will lead to governmental development planning and influence.Lewis39。s opinion, the real bottleneck is not the shortage of capital, but lack of entrepreneurial abilities. Potential entrepreneurs are hindered in their decisionmaking by institutional factors: either group considerations play a great role and hinder the potential entrepreneur, or entrepreneurs aim at personal gains at the cost of others and are thus equally detrimental to development. In view of the lack of enterpreneurial abilities there is a need for a mechanism of incentive and pressure which will automatically result in the required decisions. According to Hirschman, not a balanced growth should be aimed at, but rather existing imbalances— whose symptoms are profit and losses—must be maintained. Investments should not be spread evenly but concentrated in such projects in which they cause additional investments because of their backward and forward linkages without being too demanding on entrepreneurial abilities. Manufacturing industries and import substitutions are relevant examples. These first investments initiate further investments which are made by less qualified entrepreneurs. Thus, the strategy overes the bottleneck of entrepreneurial ability. The theory gives no hints as to how the attitude of entrepreneurs and their institutional influence will be changed in time.P. RosensteinRoden, ‘Problems of Industrialization of Eastern and Southeastern Europe,” Economic Journal (JuneSeptember, 1943). H. Leibenstein, Economic backwardness and economic growth (1957). R. Nelson, “ A theory of the lowlevel equilibrium trap in underdeveloped economies,” AER (Dec. 1956). W. Rostow, The stages of economic growth (1960). R. Nurkse, Problems of capital formation in underdeveloped countries (1953). Structuralist analysis: rigidities, lags, shortage and surpluses, low elasticities of supply and demand. G. Myrdal. Economic theory and underdeveloped regions(1957). R. Prebisch, “The economic development of Latin America and Its principal problems”, Economic Bulletin for Latin America 7 (1950). H. Singer, “ Gains and losses from trade and investment in underdeveloped countries,” AER (may 1950). (3) 在20世紀(jì)60年代后期至70年代初期，發(fā)展經(jīng)濟(jì)學(xué)更加注重貧困和收入分配。注意到發(fā)展中國(guó)家之間的差異性，總體增長(zhǎng)模型被國(guó)別的微觀化模型所取代，國(guó)別的研究和經(jīng)驗(yàn)研究受到越來(lái)越多的重視，新古典經(jīng)濟(jì)學(xué)的基本原理被應(yīng)用到發(fā)展中國(guó)家的政策研究。(iii) exploitation of economies of scale。 ine distribution effect on savings. The endogeneity of population growth: Demographic transition。2. high birth rates, low death rates and high growth rate。 this strategy is called targeting. Obviously targeting generally is associated with lower fertility rates. A change in the demographic regime from hoarding to targeting can lead to a drastic lowering of the fertility rate.The costs of childrenThese costs take two forms. First, there are what might be called the direct costs of children: they need to be fed, clothed, kept in good health, looked after, and schooled. Second, there are the indirect or opportunity costs of children that are measured by the amount of ine foregone in the process of bringing up the child.Increase in rental ine, which is panel (a), increase in wage ine results in panel (b). (62) Effects of population growth on economic development(1) Negative effectsMalthusian population model: population growth effects on per capita welfare are negative. Whenever wages rise above subsistence, people marry earlier and have more children, which depresses the wage to its biological minimum. Thus in the long run, the endogeneity of population keeps per capita ine at some stagnant subsistence level.Growth model: In the HarrodDomar model, population growth has an unambiguously negative effect on the rate of growth. In the Solow model: population growth has no ultimate effect on the rate of growth in the Solow model, but it lowers the steadystate level of the per capita capital stock, and in this way affects the level of per capita ine. Effect on savingsFaster population growth lowers the aggregate rate of savings.Effect on inequality and povertyA high rate of population growth will exacerbate the poverty prob