生育政策调整是否会影响我国“碳达峰”目标的实现?——基于STIRPAT和Leslie模型的实证研究

以中国人口生育政策调整为研究背景,基于STIRPAT模型和Leslie模型综合考察中国人口生育政策调整可能对实现“我国二氧化碳排放力争2030年前达到峰值”目标所带来的影响。结果表明,除了经济发展水平、能源技术水平、能源消费结构等因素外,人口年龄结构对人均碳排放也具有显著影响。在论文设置的四种生育率情景下,人口总量峰值分别出现在2025年、2027年、2031年和2027年。若生育政策调整能够有效提高社会总和生育率,人口规模和人口年龄结构的变化会使碳排放总量峰值推后出现。因此,中国逐步放宽的人口生育政策可能会给实现碳达峰目标带来一定压力。     

Population growth: A pure welfarist approach

In this study we propose a framework based on welfarist principles to deal with several issues concerned with population economics models, such as the Repugnant Conclusion, both in absolute and relative sense, the shape of childbearing costs and population dynamics, under both normative and positive perspectives. We show that the relative critical level criterion can avoid both the assumption of high childbearing costs and the absolute repugnant conclusion (ARC) but cannot avoid the relative repugnant conclusion (RRC). Moreover, optimal fertility is increased by technological shocks and displays cycles. Both ARC and RRC can be avoided by extending the model to a decentralized economy with consumption externalities; in the latter model, a technological shock reduces long‐run fertility and can generate cycles along the transitional path.     

Population dynamics and utilitarian criteria in the Lucas–Uzawa Model

This paper introduces population growth in the Uzawa–Lucas model, analyzing the implications of the choice of the welfare criterion on the model's outcome. Traditional growth theory assumes population growth to be exponential, but this is not a realistic assumption (see Brida and Accinelli, 2007). We model exogenous population change by a generic function of population size. We show that a unique non-trivial equilibrium exists and the economy converges towards it along a saddle path, independently of population dynamics. What is affected by the type of population dynamics is the dimension of the stable manifold, which can be one or two, and when the equilibrium is reached, which can happen in finite time or asymptotically. Moreover, we show that the choice of the utilitarian criterion will be irrelevant on the equilibrium of the model, if the steady state growth rate of population is null, as in the case of logistic population growth. Then, we show that a closed-form solution for the transitional dynamics of the economy (both in the case population dynamics is deterministic and stochastic) can be found for a certain parameter restriction.     

On the interaction between education and social security

This paper uses an overlapping generations model with endogenous fertility choices to analyze the quantitative costs and benefits of subsidizing higher education, paying particular attention to the interaction between such policy and the sustainability of the social security system. The paper focuses on the demographic change as the mechanism that link both policies. It is found that an increase in education subsidies changes the educational composition of the population and lowers average fertility. Lower average fertility and higher life expectancy of educated individuals translates into changes in the age structure of the population that requires an increase in the social security tax rate in order to balance the pension budget. Such process reduces the welfare benefits of this educational policy since the rise in social security taxes lowers the after-tax lifetime earnings of almost all individuals born in the period of the policy reform and over.     

PLAYING THE FERTILITY GAME AT WORK: AN EQUILIBRIUM MODEL OF PEER EFFECTS

We study workplace peer effects in fertility decisions using a game theory model of strategic interactions among coworkers that allows for multiple equilibria. Using register‐based data on fertile‐aged women working in medium‐sized establishments in Denmark, we uncover negative average peer effects. Allowing for heterogeneous effects by worker type, we find that positive effects dominate across worker types defined by age or education. Negative effects dominate within age groups and among low‐education types. Policy simulations show that these estimated effects make the distribution of where women work an important consideration, beyond simply if they work, in predicting population fertility.     

It's a Sin—Contraceptive Use,Religious Beliefs,and Long‐run Economic Development

This study presents a novel theory on the interaction of social norms, fertility, education, and their joint impact on long‐run economic development. The theory takes into account that sexual intercourse is utility enhancing and that the use of modern contraceptives potentially conflicts with prevailing social norms (religious beliefs). The theory motivates the existence of two steady states. At the traditional steady state, the economy stagnates, fertility is high, education is minimal, and the population sustains a norm according to which modern contraceptives are not used. At the modern steady state, the population has abandoned traditional beliefs, modern contraceptives are used, fertility is low and education and economic growth are high. Social dynamics explain why both equilibria are separated by a saddlepoint‐equilibrium (a separatrix), i.e. why it is so hard to transit from the traditional regime to the modern regime.     

Are things moving? On demographic processes and social policy

Some recent positive changes in demographic trends in the Soviet Union are described. These include an increase in life expectancy in 1986, particularly for males, and an increase in the birth rate, although fertility in European Russia is still below replacement level. The author then considers how social policy, including family policy, can be expected to influence demographic variables in accordance with the country's needs, particularly in light of major differences among regions in population dynamics. He concludes by considering the relationship between demographic factors and democracy.     

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。     

Child policy ineffectiveness in an overlapping generations small open economy with human capital accumulation and public education

Motivated by the recent decrease in the number of children experienced in several developed countries, in this paper we consider a small open economy model with overlapping generations, endogenous fertility and human capital formation through public education, and look at the role the government can play in affecting fertility through the widely used child allowance policy. Contrary to conventional view, we show that the public provision of child allowances is fertility-neutral in the long run, that is it is not effective as a pro-natalist policy, while also reducing human capital accumulation. In contrast, the financing of the public education system is beneficial to both fertility and human capital. These results hold in the cases of both fixed and time cost of children.     

The complex effects of demographic heterogeneity on the interaction between the economy and population

This paper combines population dynamics and macroeconomics in a world with structural unemployment. A general demo-economic framework, including age structure, is used to investigate the dynamical role played by fertility heterogeneity between employed and unemployed individuals. Several noteworthy dynamic features arise. First, under Malthusian conditions, i.e., when the fertility of unemployed individuals always lies below that of wage earners, the interaction between heterogeneous fertility and age structure may lead to sustained oscillations depending on the age patterns of entry in the labour market. This is an example of stable Malthusian cycle. Second, under post-Malthusian conditions, both transient and robust chaotic phenomena may appear.     

人口红利转变、老龄化与提高退休年龄

中国人口生育水平的下降和平均预期寿命的延长,导致原来的人口红利出现了转变的趋势,也造成了老龄化负担的加剧。在这种情况下,实行提高退休年龄的政策具备了某种可能性,因为人口红利的逐渐消失和劳动力供求的逆转可能成为提高退休年龄的推力,而养老金制度的老龄化危机则成为提高退休年龄的拉力。在现实条件下,考虑这一政策对城镇就业的冲击以及劳动力异质性的影响,应该实施渐进缓慢、逐步提高退休年龄的政策。     

Growth and welfare effects of monetary policy with endogenous fertility

This paper investigates the economic growth and social welfare implications of monetary policy in an endogenous growth model with endogenous fertility. We show that, in the money-in-the-utility-function framework, endogenous fertility governs the validity of money superneutrality, the transitional dynamics of an anticipated monetary policy, and the optimal monetary policy. Along a balanced growth path, monetary growth increases fertility and reduces the economic growth rate if consumption and real balances are complements or are independent. However, monetary expansion may decrease fertility and increase economic growth if consumption and real balances are substitutes. Generally speaking, the superneutrality of money does not hold in the presence of endogenous fertility. More importantly, with endogenous fertility, the Friedman (1969) rule is no longer a welfare-maximizing monetary policy. We also show that an anticipated inflation induces the transitional dynamics of fertility and the economic growth rate even though the intertemporal elasticity of substitution equals unity. This differs from the conventional notion in the existing literature.     

Economic growth, labor market and demographic patterns

This study addresses the dynamic interaction between income growth, patterns of demographic variables, and characteristics of the labor market. We attempt to provide an endogenous explanation for the origin and nature of long-run sustained oscillations in the population and in economic variables. First, we develop an economic growth model containing unemployment. The resulting dynamics reveal that the emergence of irregular sustained oscillations is related to the lack of sensitivity in wage growth to changes in the employment rate. Next, labor force growth is endogenized in the basic model through micro-founded fertility choices of individuals. By introducing the endogenous fertility rate into the basic model, we generate a demographic transition. Next, consistent with Malthusian cycle literature, the inevitable time lag between individual reproductive decisions and subsequent market needs, in conjunction with a highly specialized labor force, appear to be the primary source of such long-run oscillations. Finally, the model predicts that raising the age of entry into the labor force increases economic growth.     

Demographic links to savings in life cycle models: identification of issues for LDCs

The author considers the potential for a link between the recent pattern of demographic transition and intertemporal and inter-country variations in savings rates. Fertility, infant mortality, life expectancy, and levels of female and child labor force participation are among the various demographic factors which affect national savings rates through their effects upon age structure, age-specific individual savings behavior, and their general equilibrium effects upon interest rates, wage rates, and income distribution. The author establishes a simple discrete time life cycle model of savings, explains the issues related to age structure, and discusses the effect of age-specific savings functions, the general equilibrium effects of demographic factors, the effects of life expectancies and child mortalities, and the nature of social security coverages in less developed countries, as well as issues which are especially important for less developed countries. A new strategy for empirically evaluating demographic policies is proposed. That is, one can estimate the age profile of earnings, saving and fertility rates from household survey data. The life tables can then be used to compute the aggregate savings rate and population size. Any demographic policy which affects the fertility rate, life expectancy, and investment in the quality of children will change the aggregate saving and population growth rates. These two aggregate effects could be compared to evaluate demographic policies. The author stresses, however, that changes in different demographic factors will have different short-run and long-run effects upon the savings rate which will also depend upon whether such changes are transitory or permanent.     

Fertility and development: the roles of schooling and family production

This paper presents a quantitative theory of development that highlights three mechanisms that relate schooling, fertility, and growth. First, we point out that in the early stages of development, fertility and schooling may rise together as the schooling of younger children increases their relative contribution to family income when they turn working age. Second, the model contains a supply-side theory of schooling that generates a rise in schooling independent of technological change. Third, we introduce a direct negative effect of industrialization on fertility that does not operate through human capital and the quantity-quality tradeoff. An initial quantitative assessment of the theoretical mechanisms is conducted by calibrating and applying the model to United States history from 1800 to 2000. We find that the demise in family production is an important factor reducing fertility in the 19th century and schooling of older children is dominant factor reducing fertility in the 20th century. The same model is applied to England from 1740 to 1940, where we offer two complimentary explanations for the rise in fertility from 1740 to 1820. The first is based on the rapid expansion in the cottage industry and the second on the increased relative productivity of children. We also find that the subsequent fall in fertility from 1820 to 1940 cannot be explained without introducing child labor/compulsory schooling laws.     

Italy’s demographic trap: Voting for childcare subsidies and fertility outcomes

In this paper we study how population aging impacts the age distribution of the voting electorate and voters’ choices over childcare subsidies. We build a computable general equilibrium framework populated by heterogeneous agents who, over the course of their life-cycle, make endogenous and age-dependent fertility choices. The model is calibrated to match economic and population outcomes of the Italian economy. Child support favors young and fertile cohorts but can also impact all population subgroups through changes in prices, income taxation and population growth. A probabilistic voting model is used to measure voting outcomes over a range of childcare subsidy levels and tax policies. Our findings show that childcare subsidies have a positive impact on the total fertility rate and are welfare improving when financed with both capital and labor income taxation and in combination with lower pension contribution rates. A 10 percent increase in the level of subsidies can increase the population growth rate by an average of 0.47–0.70 percentage points. We find that voting choices of different population subgroups, while depending on the tax used to finance new expenditure, lead to lower levels of childcare subsidies, lower fertility rates and to a demographic ‘trap’.     

Why did rich families increase their fertility? Inequality and marketization of child care

A negative relationship between income and fertility has persisted for so long that its existence is often taken for granted. One economic theory builds on this relationship and argues that rising inequality leads to greater differential fertility between rich and poor. We show that the relationship between income and fertility has flattened between 1980 and 2010 in the US, a time of increasing inequality, as high income families increased their fertility. These facts challenge the standard theory. We propose that marketization of parental time costs can explain the changing relationship between income and fertility. We show this result both theoretically and quantitatively, after disciplining the model on US data. We explore implications of changing differential fertility for aggregate human capital. Additionally, policies, such as the minimum wage, that affect the cost of marketization, have a negative effect on the fertility and labor supply of high income women. We end by discussing the insights of this theory to the economics of marital sorting.     

Bounded rationality,expectations, and child labour

This paper develops a model with overlapping generations, where the household's optimal fertility, child labour, and education decisions depend on the parents’ expectations or beliefs about the return to education. It is shown that there exists a range of parental income where the fertility rate is high and children participate in the labour market and receive an incomplete education if a parent believes the return to education is low. The act of participating in the labour market reduces the child's ability to accumulate human capital; thus, the action of sending a child into the labour market is sufficient to ensure that the parents’ initially pessimistic expectations are fulfilled. It is then shown that a one‐time policy intervention, such as banning child labour and mandatory education, can be enough to move a country from the positive child labour equilibrium to an equilibrium with no child labour.     

Population growth and economic and social development

This article sets forth 3 positions on population growth: 1) rapid population growth is a central development problem that implies lower living standards for the poor; 2) proposals for reducing population growth raise difficult questions about the proper domain of public policy, yet it is acceptable for governments to attempt to influence private decisions about family size; and 3) the experience in many developing countries shows that quick, effective measures can be taken to reduce fertility. Rapid population growth has slowed development because it exacerbates the difficult choice between higher consumption in the present and the investment needed to bring higher consumption in the future. As populations grow, larger investments are needed just to maintain current capital/person. It further threatens the balance between natural resources and people and creates severe economic and social problems in urban areas. Public policy must provide alternative ways for poor families to secure the benefits provided by large family size. That is, governments need to provide tangible evidence that it really is in the best interests of parents to have fewer children. Also required is greater infomation about and access to fertility control. When family planning services have been widespread and affordable, fertility has decline faster than social and economic progress alone would predict. There is a need for immediate action to improve women's status and to make education, family planning, and primary health care more available. Although economic and social progress help to slow population growth, rapid population growth hinders development. Thus, governments must act simultaneously on both fronts. Accumulating evidence on population growth in developing countries shows that is the combination of social development and family planning that reduces fertility.     

Fertility and housing

Young households in Hong Kong face particularly steep increases in house prices and low fertility despite low gender wage gaps. The model of fertility and housing in this paper explains why fertility decline need not reverse as female wages rise relative to male wages where housing land is scarce. For given house prices, demand for children may rise with female relative wages if housing comprises a sufficiently large share of childrearing. If the user cost of housing falls with rising house prices then fertility also rises. For endogenous house prices, however, growth in wages and a burgeoning working age population raises the market price of housing. In turn, fertility no longer rises with female relative wages. The analysis provides a novel mechanism whereby high population support ratios depress fertility and the results fit recent evidence that house prices affect fertility.