最优货币政策与经济增长

本文在新古典内生增长理论的框架内,建立一个带有资本累积的世代交叠模型进行研究发现,托宾效应总是具有可行性,弗里德曼规则反而是次优的;中央银行货币政策的重心仍然是控制货币供应量,通过货币扩张来促进真实和名义GDP增长.     

Optimal Monetary Policy

Optimal monetary policy maximizes the welfare of a representative agent, given frictions in the economic environment. Constructing a model with two sets of frictions—costly price adjustment by imperfectly competitive firms and costly exchange of wealth for goods—we find optimal monetary policy is governed by two familiar principles. First, the average level of the nominal interest rate should be sufficiently low, as suggested by Milton Friedman, that there should be deflation on average. Yet, the Keynesian frictions imply that the optimal nominal interest rate is positive. Second, as various shocks occur to the real and monetary sectors, the price level should be largely stabilized, as suggested by Irving Fisher, albeit around a deflationary trend path. Since expected inflation is roughly constant through time, the nominal interest rate must therefore vary with the Fisherian determinants of the real interest rate. Although the monetary authority has substantial leverage over real activity in our model economy, it chooses real allocations that closely resemble those which would occur if prices were flexible. In our benchmark model, there is some tendency for the monetary authority to smooth nominal and real interest rates.     

On Optimal Lifetime Redistribution Policy

In this paper, we examine various aspects of the optimal lifetime redistribution policy within a cohort. We characterize the optimal tax policy when society consists of individuals who do not differ only in productivity, but also in time preference. We extend Diamond's analysis on nonlinear taxation of savings into the three-type and four-type models. To gain a better understanding of the lifetime redistribution, the problem is also solved numerically. Our results provide a rationale for distortions (upward and downward) in savings behavior in a simple two-period model where high-skilled and low-skilled individuals have different nonobservable time preferences beyond their earning capacity. If we interpret our model so that instead of private savings there is public provision of pension in the second period, then in the three-type model, we find a nonmonotonic pattern of the replacement rates. The numerical results suggest that retirement consumption is less dispersed than the first-period consumption in a paternalistic case. Paternalistic government policy also increases second-period consumption compared to the welfarist case.     

Optimal Tax-Transfer Systems and Redistributive Policy

In this paper we develop optimal yardsticks to gauge the effectiveness of given tax and benefit policies in reducing inequality. We show that the conjunction of the optimal tax and optimal benefits policies constitutes the optimal tax-and-benefit policy, given the tax and benefit budget sizes. A decomposition formula enables trends in the inequality impact of taxes and benefits to be explained in terms of changing policy effectivess (targeting) and budget size effects. The analysis incorporates a distributional judgement parameter, for sensitivity analysis, and concludes with an examination of the Finnish case for the period 1971–1990.
JEL Classification : D 63     

Optimal Tax Policy under Environmental Quality Competition

This paper studies the socially optimal emission and commodity tax policy when consumers are willing to pay a price-premium for environmentally friendlier variants of a commodity vertically differentiated in environmental quality. The first-best levels of quality can be obtained by a combination of a uniform ad valorem tax and an emission tax (or a subsidy for buying green products). The first-best emission tax is higher than the social valuation of the positive externality associated with average environmental quality. Regardless of environmentally conscious consumers, if only one instrument is available, the second-best emission tax is equal to the social valuation of the positive externality associated with average environmental quality. A uniform ad valorem tax increases welfare only if the social valuation of the positive externality associated with average environmental quality is low enough.     

Monetary Policy Delegation and Optimal Wage Indexation

This note shows that delegation of policy to a central banker who puts more weight on inflation stabilization than does the rest of society could reduce the alleged social inefficiency of private wage indexation decisions that arises in models of discretionary monetary policy.     

Optimal Fiscal Policy with Endogenous Time Preference

This paper studies the role of Ramsey taxation under the assumption that the individual rate of time preference is determined by the publicly provided social level of education. We show how intertemporal complementarities of aggregate human capital can generate multiple equilibria and we examine the role of endogenous fiscal policies in equilibrium selection. Our analysis implies a lower optimal government size due to the effect of human capital on time preference.     

Stochastic Optimal Growth with Unbounded Shock

This paper considers a neoclassical optimal growth problem where the shock that perturbs the economy in each time period is potentially unbounded on the state space. Sufficient conditions for existence, uniqueness, and stability of equilibria are derived in terms of the primitives of the model using recent techniques from the field of perturbed dynamical systems. Journal of Economic Literature Classification Numbers: C61, C62, O41.     

内部货币与我国最优关税政策研究

本文将内部货币引入一个包含两国两商品的纯交换经济,在考虑贸易关税的情形下,将此拓展成一个Nash关税博弈模型。我们用2005年中国与世界其他国家(ROW)的产出和双边贸易数据对该贸易模型进行数值分析,考察一般经济均衡条件下内部货币的引入对我国与ROW最优关税政策的影响。研究表明:(1)内部货币对贸易双方关税博弈的Nash均衡有显著影响,即相对于无内部货币的情形,内部货币的存在将削弱我国在关税博弈中的关税报复力量。(2)中国在2005年的实际关税接近于不考虑ROW关税报复时的最优关税水平及Nash均衡关税,而ROW当时的实际关税却远低于其最优关税和Nash均衡关税水平,这说明我国在2005年所采取的关税政策合乎本国利益。     

贸易政策、增长和就业

直到现在,理论模型还去无法把贸易政策与更快的均衡增长联系起来,而且,实证文献有严重的数据方面的问题,因此,经济学家们还在贸易政策与经济运行的关系上争论不休。但是,最近的内生增长理论已经提供了更坚实的理论基础。有越来越多的证据表明,在外向型经济中,新技术能更快地被采用,外向型的贸易政策与储蓄率之间可能还是存在着某些联系的。而且,许多研究者进行的实证分析表明,在越开放的经济中,增长速度越快,创造的就业机会越多。所以,外向型贸易政策对增长、就业可能起正面的作用。     

基于最优货币状况指数的政策评估：方法与应用

最优货币状况指数是以最优货币政策下所选择的各政策工具的实施力度之比作为相应权重而构建的货币状况指数。基于这个定义,本文构建了最优货币状况指数,分析了它在货币政策评估上的应用,得出几点主要结论：首先,不同于一般货币状况指数,最优货币状况指数除受原指数中相关参数的组合影响外,还受政策目标变量实际值与目标值偏离额的影响。其次,最优货币状况指数可以作为衡量货币政策实施效果的判断标准。再次,汇率和信贷政策与通货膨胀的关系及其在政策目标中的相对干预力度决定了名义或实际货币状况指数权重下货币政策的实施效果。     

外资准入政策与资源优化配置

改革开放40多年以来,外商投资是中国经济发展的主要动力之一,同时也对资源优化配置产生多方面影响。以2002年《外商投资产业指导目录》的调整作为准自然实验,具体分析外资准入政策放松对资源优化配置的影响。研究表明:外资准入政策显著地增大了城市-行业层面生产率的离散度,不利于资源的优化配置;但是,从企业层面来看,外资准入政策提高了规制放松行业中企业的平均生产率;除此之外,外资准入政策在地区、企业性质和创新能力等方面的影响存在显著差异,政策效力主要体现在东部地区、非国有企业和创新能力较强的行业。因此,中国进一步扩大外资开放程度和改革外资准入政策时,应考虑到外资准入政策放松对企业生产率和资源优化配置的双重影响。     

Human Capital and Optimal Policy in a Lucas-Type Model

We present a design of fiscal policy capable of providing the required incentives to make a decentralized economy with externalities move along the optimal transitional path in a Lucas-type human capital model. Journal of Economic Literature Classification Numbers: O41, E62, J24.     

Optimal Emission Policy under the Risk of Irreversible Pollution

We consider an optimal consumption and pollution problem that has two important features. Environmental damages due to economic activities may be irreversible and the level at which the degradation becomes irreversible is unknown. Particular attention is paid to the situation where agents are relatively impatient and/or do not care a lot about the environment and/or Nature regenerates at low rate. We show that the optimal policy of the uncertain problem drives the economy in the long run toward a steady state while, when ignoring irreversibility, the economy follows a balanced growth path accompanied by a perpetual decrease in environmental quality and consumption, both asymptotically converging toward zero. Therefore, accounting for the risk of irreversibility induces more conservative decisions regarding consumption and polluting emissions. In general, however, we cannot rule out situations where the economy will optimally follow an irreversible path and consequently will also be left, in the long run, with an irreversibly degraded environment.     

Optimal Drug Policy in Low‐Income Neighborhoods

The control of drug activity currently favors supply‐side policies: drug suppliers in the United States face a higher arrest rate and longer sentences than demanders. We construct a simple model of drug activity with search and entry frictions in labor and drug markets. Our calibration analysis suggests a strong “dealer replacement effect.”  As a result, given a variety of community objectives, it is beneficial to lower supplier arrests and raise the demand arrest rate from current values. A 10% shift from supply‐side to demand‐side arrests can reduce the population of potential drug dealers by 22–25,000 and raise aggregate local income by $380–$400 million, at 2002 prices.     

Public Policy for Growth and Poverty Reduction

In this paper, I would like to outline an approach to publicpolicy that focused on fighting poverty and is based on an understandingof growth and development. Such a public policy requires answeringtwo key questions. First, what are key determinants of a developmentthat benefits poor people – or what has been labelled"pro-poor growth"? And second, we need to answer the policyquestion: how can public action influence the key determinantswe identify? In putting the questions this way, we are settingourselves the task of building a dynamic public economics –a public economics of development. Given that development isthe objective, this task will require a better understandingof how to measure it. And we must also achieve a better graspof changes of behaviour in the process of development, sincechanging perspectives and behaviour are usually an integralpart of the development story. In laying our task of advancinga dynamic public economics, however, let me emphasise that shouldbe building – on – not overturning – pasttheory. In much of the work I will describe, the empirics seemto be ahead of theory. Thus one of my purposes is to highlightsome elements of an agenda for theoretical research. (JEL E6)     

Economic Policy Challenges for Sustained Growth*

This paper presents the views of the Prime Minister (as at March 1985) on some of the major economic challenges facing Australia and some of the policy soptions his government proposes to pursue in order to maintain the economic recovery without a resurgence of inflation and to improve Australia's long-term growth performance.     

Policy Uncertainty,Persistence and Growth*

This paper explores links between policy uncertainty and growth. Using an endogenous growth model in which domestic investment is characterized by irreversibilities and policy fluctuates between a high- and a low-tax regime, it shows that the magnitude of policy fluctuation and the persistence of policy jointly determine the pattern of investment and growth. Cross-section regressions confirm that for 46 developing countries over the 1970-85 period, policy uncertainty is negatively correlated with both investment and growth. Policy persistence also plays an important role.