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。     

Endogenous fiscal policies,environmental quality,and status-seeking behavior

This paper analyzes endogenous fiscal policy in an endogenous growth model where agents care about social status and environmental quality. The quest for a higher status is assimilated to a preference for capital wealth. The government uses income tax to finance infrastructure and environmental protection. We find that accounting for preferences for social status and environmental quality may lead to an allocation of tax revenue in favor of a cleanup effort to the detriment of infrastructure. Economic growth is not necessarily and negatively affected by this allocation as it is partly explained by an excessive accumulation of capital wealth due to the quest of status. Status seeking can however harm economic growth and environmental quality when its motive is important enough. Finally, we show that economic growth may be consistent with environmental preservation but is not necessarily welfare-improving as in the case of absence of status-seeking behavior.     

Hyperbolic discounting and the time-consistent solution of three canonical environmental problems

In this paper I propose a time-consistent method of discounting hyperbolically and apply it to three canonical environmental problems: (i) optimal renewable resource use, (ii) the tragedy of the commons, and (iii) economic growth and pollution. I show that, irrespective of potentially high initial discount rates, time-consistent hyperbolic discounting leads always to a steady state of maximum yield, or, if the environment enters the utility function, a steady state where the Green Golden Rule applies. While (asymptotic) extinction is a real threat under exponential discounting it is impossible under time-consistent hyperbolic discounting. This result is also confirmed for open-access resources. In a model of economic growth and pollution, hyperbolic discounting establishes the Golden Rule of capital accumulation and the modified Green Golden Rule.     

Environmental Ramsey Policy and Sustainable Balanced Growth

We study the link among economic growth, renewable natural resources and environmental policy. The context is a general equilibrium model of endogenous growth and environmental policy. We examine the conditions under which sustainable growth is both feasible and optimal, where the latter takes the form of second‐best optimal environmental Ramsey policies. We also investigate the conditions for an inverted U‐shaped relation between environmental policies and sustainable growth. We show that the combination of environmental production externalities and second‐best optimal Ramsey policies can lead to both local and global indeterminacy. The introduction of environmental policy, although well‐intentioned and designed to correct for market inefficiencies, triggers an expectations coordination problem; thereby differences in environmental quality and economic growth can be explained among countries with the same fundamentals.     

Government size and economic growth in an endogenous growth model with rent‐seeking

We explore the relationship between government size and economic growth in an endogenous growth model with human capital and an unproductive capital which facilitates rent‐seeking. With exogenous as well as endogenous time discounting, we find a non‐monotonic relationship between the size of government and economic growth. We find that with very high (low) discounting, there is a unique low (high) growth equilibrium, regardless of the size of government. For the intermediate range of discounting, there are multiple equilibria and the growth outcome depends on the size of government. With endogenous time discounting, the growth outcome is path dependent and depends on the level of inherited human capital. However, there is only one stable growth regime and the economy endogenously switches to it. When the institutional constraints on rent‐seeking are not extremely high, the stable regime is the one in which there is a high‐growth equilibrium for a smaller size of the government and for larger size, both the high‐growth and the low‐growth equilibrium coexist. When the institutional constraints on rent‐seeking are extremely high, there exists only a unique high‐growth equilibrium irrespective of the size of government. Furthermore, economies with bigger size of the government and/or with poor quality institutions will take longer to endogenously switch to this stable growth regime.     

Environment,Directed Technical Change and Economic Policy

We study the effects of an economic policy in an endogenous growth general equilibrium framework where production of consumption goods requires two resource inputs: a polluting non-renewable resource and a non-polluting labour resource. The use of the former contributes to the accumulation of pollution in the atmosphere, which affects welfare. There is a specific research sector associated with each of those resources. We provide a full welfare analysis, and we describe the equilibrium paths in a decentralized economy. We go on to study the effects of three associated economic policy tools: a tax on the polluting resource, and two research subsidies. We show that the optimal environmental policy has two main effects; it delays the extraction of the resource and with it the level of polluting emissions and it reallocates research efforts, decreasing the amount put into “grey” research to the benefit of “green” research. We also show that the environmental policy is grey-biased in the short-term, and green-biased in the long-term. Finally, we compute the optimal values for these tools.      

Taxation of a Polluting Non-renewable Resource in the Heterogeneous World

This paper extends the literature on the taxation of polluting exhaustible resources by taking international heterogeneities and national tax-setting into account. We propose a two-country Romer model of endogenous growth in which the South is endowed with the stock of an essential polluting non-renewable resource and world economic growth is driven by a northern research sector. We consider the stock of pollution as affecting global welfare. First, we characterize the optimal environmental taxation policies. Second, we examine the impacts of national taxes. Their time profile determines the extraction path, the dynamics of pollution accumulation and that of world output. Their respective levels entail inter-country interactions by altering the efficiency of the world resource allocation, the tax revenues and the resource rents. We study isolatedly the distortional and distributional effects of local taxes. Then, we completely assess the overall impact of a unilateral tax increase. Finally, we find that, even if heterogeneous countries coordinate their taxation policies to correct the global environmental problem, their divergent strategic interests cause another global, non-environmental distortion in the allocation of the resource.     

Demographic change,human capital accumulation and R&D‐based growth

Employing an overlapping generations model of R&D‐based growth with endogenous fertility and education decisions, we examine how demographic changes induced by an increase in life expectancy influence the long‐run growth rate of the economy. We demonstrate that life expectancy, when relatively low (high), positively (negatively) affects economic growth. This paper also compares the growth implications of child education subsidy policies (i.e., policies for enhancing basic education) and child rearing subsidy policies (i.e., pro‐natal policies) and demonstrate that while the child education subsidies consistently foster economic growth, child rearing subsidies may negatively affect economic growth.     

Is Environmental Protection Beneficial for the Environment?

We analyze a simple endogenous growth model with environmental interactions. Economic production generates emissions of pollutants whose environmental impact is mitigated by abatement activities financed by government expenditure; environmental quality affects preferences but does not play any productive role. We show that government intervention, by reallocating resources from capital accumulation to environmental preservation activities, allows the economy to achieve a sustainable balanced growth path. Along such a path, softer environmental policy regimes lead to win–win outcomes, fostering economic growth and improving environmental quality. Such a result needs to be interpreted as a long run outcome, but it clearly shows that the compatibility between economic growth and environmental improvement is far from automatic. Indeed, in the long run it could paradoxically be the case that both the economy and the environment benefit from low levels of environmental protection.     

Leisure time, savings and trade patterns A two-country growth model

This paper proposes a simple two-country endogenous growth model with endogenous consumption, leisure time and wealth accumulation. The model examines possible causes for the world economic growth and the existence and persistence of trade patterns between countries with different preferceces and human capital under internationally free capital mobility. We show how differences in preferences in consumption, leisure time and wealth between the two countries may affect long-run world economic growth.     

能源约束、技术进步与可持续发展——一个基于中间产品质量进步的分析框架

本文基于新熊彼特垂直创新的思想,构建了不可再生能源约束下的四部门内生增长模型,较为完整地分析了能源消耗、研发创新与经济可持续增长之间相互作用的内在机理。笔者采用n种连续中间产品产出效率来刻画技术创新,求解并讨论了社会计划最优的均衡增长路径,运用比较静态方法分析了各类参数的长期最优产出增长效应和耗能增长效应,最后得出结论并提出了相关的政策建议和进一步研究的方向。     

Renewable resource management with environmental prediction: the importance of structural specification

Environmental variability can substantially influence renewable resource growth, and as the ability to forecast environmental conditions improves, opportunities for adaptive management emerge. Using a stochastic stock‐recruitment model, Costello, et al. ( 2001 ) show the optimal management response to a prediction of favourable growth conditions is to reduce current harvests. We find this result may be reversed when environmental variability and stock are substitutes in growth, a possibility that has been ignored by resource economists. As an example, we analyze the South Carolina white shrimp fishery, finding the optimal response to a prediction of favourable overwinter conditions is to increase fall harvests.     

Endogenous strength of intellectual property rights: Implications for economic development and growth

The key institution that determines sustained growth in R&D-based growth models is the strength of intellectual property rights, which are usually assumed to be exogenous. In this paper we endogenize the strength of the intellectual property rights and show how private incentives to protect these rights affect economic development and growth. Our model explains endogenous differences in intellectual property rights across countries as private incentives to invest in property rights generate multiple equilibria. We show that the resulting institutional threshold offers an explanation for why the effect of a transfer of institutions from one country to another depends on the quality of the institutions that were imported.     

Ability transmission,endogenous fertility and educational subsidy

In this study, we attempt to investigate how educational subsidy, childcare allowance and family allowance affect economic growth and income distribution on the basis of simulation models which incorporate intergenerational ability transmission and endogenous fertility. The simulation results show that financial support for higher education can both increase economic growth and reduce income inequality, especially if the abilities of parent and child are closely correlated. In contrast with educational subsidy, raising childcare allowance or family allowance has limited impacts on growth and income inequality.     

Optimum Growth and Carbon Policies with Lags in the Climate System

We study the optimal carbon tax in an economy in which climate change, stemming from polluting non-renewable resource, affects the economy’s growth potential. Our main contribution is to introduce and explore the natural time lag of the climate system between emissions and damages to capital accumulation in an endogenous growth setting. This allows us to investigate how optimal climate policy, and its interplay with climate dynamics, affect long-run growth and the transition of the economy towards it. Without pollution decay, a higher speed of emissions diffusion steepens the growth profile of the economy. With pollution decay, this leads to lower short-run but higher long-run economic growth during transition. Poor understanding of the emissions diffusion process leads to suboptimal carbon taxes, resource extraction and growth.     

A simple endogenous growth model with endogenous fertility and environmental concern

We analyze the implications of endogenous fertility choices on both economic and environmental performances in a stylized AK‐type growth model. Differently from what traditionally assumed in the growth and environment literature, we allow pollution to be not only a by‐product of productive activities by firms but also a result of households’ behavior, as suggested by the celebrated IPAT equation. We show that along the balanced growth path equilibrium, economic growth may be non‐monotonically related to the population growth rate as agents care for the environment; moreover, demographic policies can be used both to achieve win‐win outcomes (simultaneously fostering economic growth and improving environmental quality) and to stabilize the otherwise non‐monotonic economic and population growth relationship.     

PRODUCTION AND CONSUMPTION OF EDUCATION IN A R&D-BASED GROWTH MODEL

We develop a R&D‐based growth model with endogenous accumulation of human capital. We investigate the idea that education is a good entering in the preferences of individuals. We seek to analyse how the decisions of individuals to invest in human capital can be altered by changes in economic policies and how they can be reflected on the level of growth in the long run. We show that policy changes affect growth through their effect on the decision of individuals to invest in human capital. The effects obtained depend whether individuals enjoy to acquire education or if they consider it as a ‘bad’. In the absence of any policy intervention, the level of growth can be excessive or insufficient compared with the optimum.     

A re-examination of financial development,stock markets development and economic growth

This study provides new evidence on the role of financial development and stock market development in accounting for economic growth across geographic regions and income groups. To derive feasible policy implications, we estimate not only unbalanced panel regressions with period fixed effects, but also variance decompositions of annual Gross Domestic Product (GDP) growth rates to examine what proxy measures are most important in economic growth over time and how much they contribute to economic growth. We find distinct direction, timing and strength of the causal links between financial development, stock market development and economic growth based on the results of Granger causality tests. Therefore, it may be necessary to make different efforts to achieve steady economic growth across geographic regions and income groups.     

Behavioural Economics,Hyperbolic Discounting and Environmental Policy

This paper reviews some recent research in “behavioural economics” with an application to environmental issues. Empirical results from behavioural economics provide a reminder that human behaviour is context-dependent, implying that policy may go awry if based upon models of behaviour which are inappropriate to the contexts in which decisions are made. Recognizing that agents may, in some contexts, systematically make mistakes raises challenging questions about the role of “paternalism” in government policy. The paper considers the research into hyperbolic discounting, and examines the implications for environmental policy. We develop a model of resource management under hyperbolic discounting, which shows that if a planner is unable to commit to a policy, the temptation to re-evaluate the policy in future could lead to an inadvertent collapse in the stocks of a natural resource.     

Sustainable Resource Use and Economic Dynamics

We argue that the sustainable use of natural resources has to be placed in a dynamic perspective, both in theoretical modelling and in applied research. This can be achieved by applying endogenous growth theory and other recent advances in dynamic theory. In this paper we discuss five contributions that combine the topics of natural resource use and economic dynamics. In particular, we show the common features of these contributions, thereby providing an overview of a very active and promising research area.