中国债务的福利损失分析

政府债务问题始终是经济学者研究的重要领域,它也为各国政府广泛关注。围绕着巴罗—李嘉图等价定理成立与否展开的最优债务规模引起了经济学者极大的关注,这方面的研究在中国也取得了一定的进展。在现实经济中,究竟国债政策发生变化给中国经济带来多大的福利损失,还没有学者进行相应的讨论,大多数人仅局限于参照国外公债的一些指标讨论中国公债的合理性,而没有从数量上进行福利分析。本文在一个劳动力存在着冲击和消费者受到借贷限制的市场不完善的模型中,从中国的样本经济出发,考虑政府债务政策变化带来的福利损失。     

Government Spending and Welfare with Returns to Specialization

We explore a novel channel through which government spending can stimulate consumption and welfare through its effects on aggregate productivity, without directly affecting either utility or production possibilities. In the presence of monopolistic competition and increasing returns to specialization, it is shown that government spending can partly alleviate the inefficiencies of monopolistic competition. This is because government spending generates an endogenous increase in total factor productivity by increasing the variety of intermediate goods. If the degree of increasing returns to variety is large enough, a rise in such wasteful government spending may increase consumption levels enough to increase welfare.
JEL classification : E 60     

Public debt and welfare in a quantitative Schumpeterian growth model with incomplete markets

This paper quantifies the welfare effects of counterfactual public debt policies using an endogenous growth model with incomplete markets. The economy features public debt, Schumpeterian growth, infinitely-lived agents, uninsurable income risk, and discount factor heterogeneity. Two versions of the model are specified, one with households holding equity in the group of innovating firms. The model is calibrated to the U.S. economy to match the degree of wealth inequality, the share of R&D expenditure in GDP, the firms’ exit rate, the average growth rate, and other standard long-run targets. When comparing balanced growth paths, I find large welfare gains in equilibria characterized by governments accumulating public wealth. The result is robust to the mechanism used to generate a highly concentrated wealth (i.e., preference heterogeneity or “superstar” income shocks). Welfare effects decompositions show that level effects and growth effects reinforce each other. The responses of both the intermediate goods and their market conditions are key in explaining the large level effects. The version of the model without equity is computationally easier to solve, allowing to consider transitional dynamics. Taking into account the dynamic adjustment to the new long-run equilibrium, I show that the transitional welfare costs are not large enough to change the sign of the welfare effects stemming from a change in public debt. I find that eliminating public debt would lead to a 0.8% increase in welfare, while moving to a debt/GDP ratio of 100% would entail a welfare loss of 0.5%. A decomposition analysis shows that growth accounts for approximately 50% of the overall welfare effects.     

The Ramsey model with AK technology and a bounded population growth rate

This paper generalizes the Ramsey AK model by allowing the population growth rate to be variable over time subject only to be between prescribed upper and lower limits. Contrary to the standard AK setting, convergence can occur. Moreover, monotonicity as well as an asymptotic balanced growth path equilibrium may arise in the model.     

One size may not fit all: Welfare benefits and cost reductions with optional differentiated household electricity rates

We consider optional time-of-use (TOU) pricing for residential consumers, offered by a publicly regulated electricity supplier, as an alternative to a single TOU or flat rate structure. An equilibrium model explores and quantifies the effects of such pricing on welfare, consumption, and production costs. The supplier offers to each household a menu of possible rate structures obtained by maximizing a collective welfare function subject to three restrictions: Pareto efficiency, incentive compatibility, sufficiency of supplier revenue to cover costs. Simulations based on realistic calibration of the model demonstrate that optional pricing can increase overall consumer welfare and reduce average cost.