Effect of social security on fertility and savings: an overlapping generations model

Old-age pension schemes do not exist in most developing countries, so adults bear children as security investments for the future. This phenomenon leads to unduly high rates of population growth. It has been hypothesized that introducing social security programs in such countries would increase savings rates and reduce the number of children born over the long term. The author studies the general equilibrium effects of some social security programs on rates of population growth and capital accumulation within an overlapping generations framework with endogenous fertility and savings. Specifically, Raul's overlapping generations growth model is extended to study the general equilibrium effects of payroll-tax-financed and child-tax-financed social security programs. It is shown that if the rate of intergenerational income transfers from young to old or child care cost is low, competitive equilibrium leads toward overpopulation and capital accumulation in a modified Pareto optimal sense; a social security program in such a case is therefore Pareto improving. A fully-funded system is not neutral when financed by child taxes. Finally, it is also shown that unlike in the case of exogenous fertility where competitive equilibrium attains steady state only asymptotically, fertility, when endogenous, may attain a unique globally steady state in finite time.     

人口年龄结构、养老保险制度与最优储蓄率

近年来 ,中国城镇居民的消费倾向出现了大幅度的下降。为了解释这个令人困惑的现象 ,我们首先构建了一个可以把握中国养老保险制度之基本特征的叠代模型。我们进而发现 ,人口老龄化一般说来会激励居民增加储蓄。由于人口老龄化是计划生育政策的自然结果 ,它很可能是造成中国城镇居民储蓄倾向上升的一个重要因素 ,本文中的数值模拟结果为上述判断提供了一些依据。最后 ,我们对中国的黄金律问题进行了讨论。基于多种原因 ,我们认为中国目前的储蓄率并不是社会最优储蓄率的体现 ,降低储蓄率很可能成为一个帕累托改进。     

Price stabilizing, Pareto improving policies

One possible justification for a stabilization policy is that there is volatility in macro variables that individual agents cannot insure against. We study the simplest possible extension of the stochastic two-period, one agent and one commodity OLG model, where we have added one more period, with only one potential activity, namely, trading of contingent commodities. We assume, however, that markets are incomplete. In this case the Monetary equilibrium is not Pareto Optimal and for an open set of economies an allocation where fluctuations in realized savings are removed, Pareto dominates the monetary equilibrium. This allocation may be implemented by means of a monetary/fiscal policy. The policy considered has a simple rationale, namely that it removes some of the uncertainty that agents face by reducing price, i.e interest rate volatility. We consider two fundamental sources of such volatility, namely, respectively an objective and a subjective signal about the distribution of future endowments. The first case is when agents have rational expectations while the second case is studied in the context of agents having rational beliefs, beliefs which are consistent with empirical observations but not (necessarily) correct.     

Horizontal mergers,cost savings,and network effects

We consider a horizontally differentiated oligopoly and investigate the relationship between merger cost savings and network effects for the incentives of firms to merge and for the postmerger welfare outcomes. We show that it is more profitable to be an insider rather than an outsider of the merger, unless both cost savings and network effects are too low. Mergers can improve customer and total welfare provided both cost savings and network effects are high enough. We find that the possibility for network effects to lead to a Pareto improvement through merger is shown to depend on the number of outside firms.     

INEQUALITY, REDISTRIBUTION, AND RENT-SEEKING

This paper presents a non-median voter model of redistribution in which greater inequality leads to lower redistribution. Bargaining between interest groups and politicians over exemptions implies that individuals with sufficiently high income will not pay taxes in equilibrium. Therefore, voters will set tax rates low enough so as to control the incentives for rent-seeking. An increase in inequality, by putting more income in the hands of individuals that can buy exemptions, will lead to lower equilibrium redistribution. The model can be used to account for a negative relationship between inequality and growth and provides a new explanation of why the poor do not expropriate the rich in democracies.     

Credit market imperfection,labor supply complementarity,and output volatility

This paper argues that output volatility depends on the degree of credit market imperfection. In the early stages of financial development, agents are constrained in their borrowing ability. As a result, the individual savings, affected by the labor supply, play a dual role in the economy, having repercussions on the interest rate. On the one hand, high savings imply high investment, low marginal product of capital and thus low interest rate. On the other hand, high savings affect the agents' ability to run highly productive investment projects, which increases the interest rate. When the former effect is dominant, a dynamic complementarity between individual and aggregate labor supply arises. This leads to a local and global indeterminacy of equilibrium paths. If the borrowing constraint is relaxed, the complementarity between individual and aggregate labor supply decisions weakens, equilibrium becomes globally unique and the possibility of having aggregate fluctuations in output disappears.     

Conditional Earnings Subsidies for Low Earners

In order to be eligible for in-work tax credits, it is often not enough to have low earnings. In Ireland, New Zeand the United Kingdom, for example, for eligibility, it is also required that the number of hours worked is sufficiently high. Similarly, in Belgium and France, the hourly wage rate must be sufficiently low. In this paper, I provide a justification for such additional conditions. I analyze Pareto-efficient redistribution from high to low ability individuals in a model where labor has several intensive margins. Besides labor hours, labor effort – a vector of unpleasant, but productive features of labor – is also an object of choice. Effort and ability determine the hourly wage rate. I find that conditional subsidies on earnings for low earners are optimal: the earnings of low earners should be subsidized at the margin, but only if they earn more by working more hours at a sufficiently low wage rate.     

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.     

Capital Tax Competition and Cooperation with Endogenous Capital Formation

Incorporating consumption–savings choices under a general concave utility function and hence an endogenous capital supply into a model of capital tax competition, we re‐investigate Nash equilibrium and compare it with the optimum under cooperative tax policy. In contrast to the case of fixed capital supply, it is shown that if savings sufficiently increase with the interest rate, a Nash equilibrium may be more efficient than a cooperative tax policy. Therefore, the distortionary effects of capital supply are important to issues of tax policy coordination.     

Externality Policy Reform: A General Equilibrium Analysis

We characterize Pareto‐improving and equilibrium‐preserving policy reforms in a second‐best (Diamond/Mirrlees) world with a consumption externality. A counterintuitive finding is that, starting from an initial equilibrium with no direct quantity control on the externality, it is possible that all Pareto‐improving and equilibrium‐preserving directions of change require an increase in a negative externality. We provide intuition for these results by establishing a nexus between Guesnerie's approach to designing (tax) policy reforms and the standard Kuhn–Tucker technique for identifying the manifold of feasible Pareto‐optimal states, given the instruments available to the policy maker.     

The price of deposit liquidity: banks versus microfinance institutions

Using data from Bangladesh, this article finds that the liquidity premium – the difference between the interest paid on illiquid and liquid savings accounts – is higher in commercial banks than in microfinance institutions. One possible interpretation lies in the higher prevalence of time-inconsistency among the poor. The observed difference in liquidity premia could be due to poor time-inconsistent agents willing to forgo interest on illiquid savings accounts in order to discipline their future selves.     

Optimal steady-state in stationary consumption-loan type models

We consider a stationary overlapping generations economy, and prove that an optimal steady state exists. We show that if a government intervention is needed in order to implement the optimal steady state as a competitive equilibrium, it is necessary only in a finite number of periods. If the interest rate associated with the optimal steady state equals the population rate of growth, some outside money may be required in order to make the competitive equilibrium follow the optimal steady state. We show that our existence result enables us to construct Pareto optimal competitive equilibria in some important cases.     

“Interest Rate Trap”, or Why Does the Central Bank Keep the Policy Rate Too Low for Too Long?

In this paper, we provide a framework for modeling one risk‐taking channel of monetary policy, the mechanism whereby financial intermediaries' incentives for liquidity transformation are affected by the central bank's reaction to a financial crisis. The anticipation of the central bank's reaction to liquidity stress gives banks incentives to invest in excessive liquidity transformation, triggering an “interest rate trap” – the economy will remain stuck in a long‐lasting period of suboptimal, low interest rate equilibrium. We demonstrate that interest rate policy as a financial stabilizer is dynamically inconsistent, and the constrained efficient outcome can be implemented by imposing ex ante liquidity requirements.     

Self-selection and Pareto efficient taxation

This paper analyses the set of Pareto efficient tax structures. The formulation of the problem as one of self-selection not only shows more clearly the similarity between this problem and a number of other problems (such as the optimal pricing of a monopolist) which have recently been the subject of extensive research, but also allows the derivation of a number of new results. We establish (i) under fairly weak conditions, randomization of tax structures is desirable; (ii) if different individuals are not perfect substitutes for one another in production, then the general equilibrium effects—until now largely ignored in the literature—of changes in the tax structure may be dominant in determining the optimal tax structure; in particular if the relative wage of high ability and low ability individuals depends on the relative supplies of labor, the optimal tax structure entails a negative marginal tax rate on the high ability individuals, and a positive marginal tax rate on the low ability individuals (the marnitude of which depends on the elasticity of substitution); (iii) if individuals differ in their preferences, Pareto efficient taxation may entail negative marginal tax rates for high incomes; while (iv) if wage income is stochastic, the marginal tax rate at the upper end may be 100%.Our analysis thus makes clear that the main qualitative properties of the optimal tax structure to which earlier studies called attention are not robust to these attempts to make the theory more realistic.     

Is the value added tax a useful macroeconomic stabilization instrument?

The value added tax (VAT) has been proposed as a macroeconomic stabilization instrument. This paper considers some practical implications of a variable VAT. It then develops a dynamic general equilibrium model to assess its usefulness as a stabilization instrument. A variable rate VAT would no longer be less distortionary than other taxes. It would distort between current and future consumption, i.e. savings and investment decisions, and hence raise the economic costs of taxation. Moreover, a variable VAT would be less effective in dampening business cycles than the conventional stabilization tool, an interest rate. This is because of the additional adverse supply effects. A change in the interest rate affects this period's savings and investment decisions, whereas a variable VAT rate would influence savings and investment decisions over time. A variable VAT rate is therefore unlikely to be a useful stabilization instrument.     

On the Evolution of Pareto‐Optimal Behavior in Repeated Coordination Problems

I characterize the asymptotic behavior of a society facing a repeated‐common‐interest game. In this society, new individuals enter to replace their “parents” at random times. Each entrant has possibly different beliefs about others' behavior than his or her predecessor. A self‐confirming equilibrium (SCE) belief process describes an evolution of beliefs in this society consistent with a self‐confirming equilibrium of the repeated game. The main result shows that for any common‐interest game, the Pareto‐dominant equilibrium is a globally absorbing state of the behavioral dynamics when the SCE beliefs of new entrants satisfy certain independence and full‐support properties. This result does not involve either of the usual assumptions of myopia or large inertia common in evolutionary models, nor is this result possible if only Nash rather than self‐confirming equilibria are considered.     

Do interest rate controls work? Evidence from Kenya

This paper reviews the impact of interest rate controls in Kenya, introduced in September 2016. The intent of the controls was to reduce the cost of borrowing, expand access to credit, and increase the return on savings. However, we find that the law on interest rate controls has had the opposite effect of what was intended. Specifically, it has led to a collapse of credit to micro‐, small‐, and medium‐sized enterprises; shrinking of the loan book of the small banks; and reduced financial intermediation. Because of their adverse effects on bank lending, we estimate that the interest rate controls have reduced economic growth by ¼–¾ percentage points on an annual basis. We also show that interest rate caps reduced the signaling effects of monetary policy. These suggest that (1) the adverse effects could largely be avoided if the ceiling was high enough to facilitate lending to higher‐risk borrowers and (2) alternative policies could be preferable to address concerns about the high cost of credit.     

Loss aversion and social security: a general equilibrium approach

Introducing an intertemporal model of loss aversion, I study the role of social security in determining intergenerational redistribution when consumers have reference-dependent preferences with loss aversion. Using a unified social security model in which different social security plans are specified via different degrees of fundedness, I examine the effect of the transition from a less funded system to a more funded one on savings, consumption, and capital accumulation for an OLG production economy. A general equilibrium analysis shows that the direction of intertemporal equilibrium is dependent on how the total savings responds to the interest rate change, but the effect of the payroll tax on capital accumulation is ambiguous. By deriving closed-form solutions, I find that an increase in fundedness intensity unambiguously increases capital accumulation in steady states, while the tax effects on consumption and savings are not conclusive. Moreover, simulation exercises show that when consumers are prone to over-consume because they care more about the contemporaneous gain utility, the fully funded system may help the individuals smooth out their lifecycle consumption.     

金融发展、资本积累与内生增长:一个评述

本文以资本外溢AK内生增长模型为基础,对金融发展、资本积累与经济增长关系的理论研究和经验分析作了一个文献综述.理论研究表明:金融发展通过提高储蓄转化为资本比率、改善投资配置效率和改变储蓄率等途径促进资本积累和经济增长;金融发展与经济增长之间呈互相促进、互为因果的双向关系,并形成金融发达、经济高增长和金融欠发达、经济低增长的双重均衡.经验分析显示,金融发展与经济增长之间呈显著正相关关系,这证实了金融发展与内生增长理论的预测.