Population and Economic Growth Under Different Growth Engines

Using a growth model with physical capital accumulation, human capital investment and horizontal R&D activity, this paper proposes an alternative channel through which an increase in the population growth rate may yield a non‐uniform (i.e., a positive, negative, or neutral) impact on the long‐run growth rate of per‐capita GDP, as available empirical evidence seems mostly to suggest. The proposed mechanism relies on the nature of the process of economic growth (whether it is fully or semi‐endogenous), and the peculiar engine(s) driving economic growth (human capital investment, R&D activity, or both). The model also explains why in the long term the association between population growth and productivity growth may ultimately be negative when R&D is an engine of economic growth.     

Fiscal Policy and Long-run Growth in R&D-based Models with Endogenous Market Structure

This paper shows that in a model of endogenous growth that does not exhibit the scale effect, taxes on consumption and labor income and the level and composition of public expenditure have no effect on steady-state growth. The only fiscal instruments that affect steady-state growth are taxes on asset and corporate income. In line with standard intuition, tax rates and public expenditure have level effects on income per capita. These results emphasize that although growth is endogenous, in the sense that it is determined by the model and it is subject to policy action, instruments that work by changing market size do not affect it. Effective growth-enhancing policies operate through the interest rate.     

中国未来不同生育水平下的经济增长后果比较研究

对中国未来90年不同生育水平下的经济增长后果进行了人口-经济动态模拟。在生育水平过低导致劳动力减少过快、人口老龄化过重、劳动负担加重的情况下,将使经济增长大大放缓;而较高的生育水平下,虽然经济增长速度略快,但是人均GDP增长速度慢于中方案生育水平下的经济增长,并且人均GDP水平也具有较大差异。完善当前生育政策,使生育水平稳定在1.9-2.0之间,如此人口在本世纪缓慢地减少也将有利于我国的经济增长和人均生活水平的提高。同时,在低生育水平下,依靠劳动增加和资本积累的粗放型经济增长将不复存在,经济发展方式转变是必然选择,技术创新、技术进步将是未来经济增长首要源泉。     

Twin Engines of Growth: Skills and Technology as Equal Partners in Balanced Growth

We develop an endogenous growth model in which skill acquisition by households and innovation by firms make distinct contributions to productivity growth. Nevertheless, the incentives faced by firms and households are inextricably linked because skills are required to implement new technologies. Skills and technologies are dynamic complements but, because their production complementarity is inherently bounded, they are equal partners in driving growth: neither can generate sustained growth alone. Our model has important implications for the effectiveness of alternative growth-promoting policies, for interpretating the empirical relationship between growth and schooling, and the relationship between growth and intergenerational wage dispersion.     

On the Effects of Redistribution on Growth and Entrepreneurial Risk-taking

This paper investigates the effects of redistributive taxation on occupational choice and growth. We discuss a two-sector economy in the spirit of Romer (1990). Agents engage in one of two alternative occupations: either self-employment in an intermediate goods sector characterized by monopolistic competition, or employment as an ordinary worker in this sector. Entrepreneurial profits are stochastic. The occupational choice under risk endogenizes the number of firms in the intermediate goods industry. While the presence of entrepreneurial risk results in a suboptimally low number of firms and depresses growth, nonlinear tax schemes can sometimes compensate negative effects by ex post providing social insurance.     

经济增长与银行的合约选择

由于信息不对称对资本积累过程的影响,为了维持足够的经济增长速度,银行必须考虑签订消除贷款人与借款人之间信息不对称的合约,让更多的可贷资金流向生产性投资,推动经济走向更高的资本积累路径。     

Agricultural Productivity Growth and Escape from the Malthusian Trap

Industrialization allowed the industrialized world of today to escape from the Malthusian regime characterized by low economic and population growth and to enter the post-Malthusian regime of high economic and population growth. To explain the transition between these regimes, we construct a growth model with two consumption goods (an agricultural and a manufacturing good), endogenous fertility, and endogenous technological progress in the manufacturing sector. We show that with an exogenous increase in the growth of agricultural productivity our model is able to replicate stylized facts of the British industrial revolution. The paper concludes by illustrating that our proposed model framework can be extended to include the demographic transition, i.e., a regime in which economic growth is associated with falling fertility.     

内生经济增长理论框架下的市场失效与财政政策

内生经济增长理论认为,知识和人力资本的外部效应与创新带来的垄断势力推动经济增长的同时,也会带来非帕雷托最优的经济增长收入分配的不公平,将阻碍经济增长;加快知识和人力资本积累、促进技术进步以及缓解收入分配不公平的财政政策能纠正市场失效,使长期经济增长达到社会最优.     

资源约束条件下长期经济增长的动力机制--基于内生增长理论模型的研究

文章通过将存量有限且不可再生的自然资源引入生产函数,构建了一个产品种类扩张型的四部门内生增长模型。首先,通过对模型的市场均衡分析,给出了平衡增长路径的经济增长率以及均衡解存在的一个充分性条件,系统地探讨了在人口增长、自然资源不断耗竭的约束条件下内生技术进步促进长期经济增长的动力机制;其次,通过对平衡增长路径进行比较静态分析,讨论了各经济变量以及经济环境参数的变化对稳态增长率的影响效应及其作用机制,并给出其经济学解释;最后是综合结论及政策涵义。     

金融发展与经济增长:国外研究综述

本文较为详细地介绍了近年来国外金融发展与经济增长关系的研究文献,并对有关研究进行了评述.主要内容包括金融发展与经济增长的关系,金融结构主义和金融抑制主义的主要观点的产生、发展(演变路径)和研究现状.     

Does the Mortality Decline Promote Economic Growth?

This paper analyzes qualitatively and quantitatively the effects of declining mortality rates on fertility, education and economic growth. The analysis demonstrates that if individuals are prudent in the face of uncertainty about child survival, a decline in an exogenous mortality rate reduces precautionary demand for children and increases parental investment in each child. Once mortality is endogenized, population growth becomes a hump-shaped function of income per capita. At low levels of income population growth rises as income per capita rises leading to a Malthusian steady-state equilibrium, whereas at high levels of income population growth declines leading to a sustained growth steady-state equilibrium.     

Population Genetics and Economic Growth

This paper builds an age-structured model of human population genetics in which explicit individual choices drive the dynamics via sexual selection. In the model, agents are endowed with a high-dimensional genome that determines their cognitive and physical characteristics. Young adults optimally search for a marriage partner, work for firms, consume goods, save for old age and, if married, decide how many children to have. In accord with the fundamental genetic operators, children receive genes from their parents. An agent's human capital (productivity) is an aggregate of the received genetic endowment and environmental influences so that the population of agents and the economy co-evolve. After calibrating the model, we examine the impact of physical, social, and economic institutions on population growth and economic performance. We find that institutional factors significantly impact economic performance by affecting marriage, family size, and the intergenerational transmission of genes. The principal novel findings are that i) genetic diversity has a nonmonotone causal impact on population size and economic performance; ii) an endogenous population threshold exists which, absent frictions, causes societies with declining populations and output to reverse course and grow; and iii) that the emotion love substantially accelerates economic growth by increasing genetic diversity just enough, which we term The Goldilocks Principle.     

Technological Change and Population Growth

What is the relationship between the rate of population growth and the rate of technological change? To answer this question, I discuss a model where increasing returns generate long-run growth but where the scale effect is absent. More precisely, the model predicts that steady-state productivity growth does not depend on population size because an increase in population size leads to entry. The resulting crowding-in effect generates dispersion of R&;D resources across firms and offsets the positive effect of the scale of the economy on the returns to R&;D. Changes in population size have only transitory effects on productivity growth. This desirable property allows me to introduce population growth in the model and study the effects of demographic shocks. The predicted patterns of growth, entry, and change in industrial structure match the experience of several industrialized countries. In addition, they match several of the empirical observations cited as evidence against standard models of endogenous technological change.     

工业经济的节约型增长及其动力

利用资本、能源和劳动三要素随机前沿成本模型对中国工业成本节约之源进行研究,将成本变动分解为技术进步、价格调整、效率改进与规模变动效应。规模扩大是推动2000—2007年工业成本增长的首要因素,其次是价格调整效应。技术进步和效率改进共同推动节约型增长,前者对节约型增长的影响更广泛、深入。主要依靠技术进步实现节约型增长,是新世纪以来工业增长的重要特征。效率改进提供的额外动力使轻工业成为节约型工业增长的先导部门。     

Too Much of a Good Thing? The Quantitative Economics of R&D‐driven Growth Revisited

This article augments an R&D‐based growth model of the third generation with human capital accumulation and impure altruism, calibrates it with U.S. data, and investigates whether the market provides too little or too much R&D. For benchmark parameters, the market share of employment in R&D is close to the socially optimal solution. Sensitivity analysis shows that the order of magnitude of possible deviation between market R&D and optimal R&D is also smaller than suggested by previous studies. Small deviation of total research effort, however, can be compatible with large sectoral misallocations. Furthermore, the model allows for two additional channels through which population growth may affect the resource allocation so that its overall economic impact is no longer predetermined as positive. Numerical calibrations show that economic growth at the average rate in the U.S. over the last century can be consistent with a small and probably negative partial correlation between population growth and economic growth.     

Climate and Scale in Economic Growth

This paper introduces new data on climatic conditions to empirical tests of growth theories. We find that, since 1960, temperate countries have converged towards high levels of income while tropical nations have converged towards various income levels associated with economic scale and the extent of the market. These results hold for a wide range of tests. A plausible explanation is that temperate regions' growth was assisted by their climate, perhaps historically for their transition out of agriculture into sectors whose productivity converges across countries, while tropical countries' growth is relatively more dependent on gains from specialization and trade.     

人口转变、经济发展与卫生支出增长——以人口普查为基础的因素分解

采用因素分解方法考察中国卫生支出在过去近30年的增长特点,将卫生总费用增长及卫生总费用占GDP比重的变化,分解为人口数量增长、人口结构变动、健康模式变化和非人口学因素影响四个独立可比的部分。结果显示,尽管非人口学因素决定着卫生总费用增长,人口学因素却主导着卫生总费用占GDP比重的变化。人口学因素中,人口总量缓慢增长和人口结构快速转变推动着卫生支出规模不断上升,但健康模式变化显著削弱了这种趋势。     

Endogenous Growth and Natural Resource Scarcity

Endogenous growth theory has rekindled interest in the role of innovation in determining long-term economic growth. Generally, this body of literature has ignored the contribution of natural resources to growth or the role of innovation in overcoming resource scarcities. The latter problem has been a focus of resource economics for many years, but innovation is usually modelled as exogenous rather than endogenous technological change. Recent investigations in political economy have additionally suggested that the supply of innovation may itself be constrained by resource scarcities, especially in the developing world. The following paper attempts to bridge these theoretical gaps through the formal analysis of two issues: First, a simple Romer-Stiglitz model of endogenous growth with resource scarcity and population growth is developed to determine the optimal balanced growth path for the economy. Second, the basic model is extended to allow for the possibility of resource availability constraining the supply of innovation, so that in the long run innovation net of any resource constraint is zero. However, under the latter conditions it is still possible to avoid resource exhaustion and thus achieve a constant level of per capita consumption in the long run. The paper therefore demonstrates that endogenous growth can overcome resource scarcity, but the outcome in the long run depends critically on assumptions concerning any constraints imposed by resource availability on the generation of innovation.     

Income Inequality and Economic Growth: Evidence from American Data

While most cross-country studies find a negative relationship between income inequality and economic growth, studies that use panel data suggest the presence of a positive relationship between inequality and growth. This paper uses a cross-state panel for the United States to assess the relationship between inequality and growth. Using both standard fixed effects and GMM estimations, this paper does not find evidence of a positive relationship between inequality and growth but finds some evidence in support of a negative relationship between inequality and growth. The paper, however, shows that the relationship between inequality and growth is not robust and that small differences in the method used to measure inequality can result in large differences in the estimated relationship between inequality and growth.     

Growth States and Shocks

GDP growth typically vibrates with modest variation around a mean of a few percent per year, but periodically, mean growth undergoes a major shift, vibrating thereafter around a new level. I present a transmission mechanism with nonlinear dynamics that endogenously translates random sectoral shocks into just this sort of behavior, creating what might be thought of as multiple growth states. Small shocks cause vibration within a state. Sufficiently large shocks cause a state change. Behind the nonlinear dynamics lies essentially the same dynamic externality that drives the new-growth theory models. The relative balance of endogenous versus exogenous growth determines whether the economy will have multiple stable growth states. The model can generate data which looks much like the data generated by a Markov process of the sort identified in Hamilton (1989) or a trend-breaking process as in Perron (1989). The model has two output processes. Input factors are drawn into the leading process, where learning-by-doing further increases that process's technological lead. If the leading process is also the inherently high-growth process, then growth is fast for both technologies. Shocks to preferences and technologies cause endogenous switching of the leading sector role between the high-growth and slow-growth processes.