Optimal cyclicity and chaos in the 2-sector RSS model: An anything-goes construction

We present a simple and transparent construction that furnishes, for any pre-chosen dynamic, particular instances of the 2-sector version of the Robinson–Solow–Srinivasan model that yield the chosen dynamic, including optimal topologically chaotic programs and those that exhibit cycles of any given period. The construction is expressed in terms of ξ, the marginal rate of transformation of capital from one period to the next with zero consumption, an important summary statistic of the model discovered by Khan and Mitra. Our construction relies on theorems due to Li–Yorke and Sharkovsky, and complements earlier work on chaotic dynamics in the RSS model.     

Ergodic chaos, learning and sunspot equilibrium

Summary. In this paper we construct sunspot equilibria that arise from chaotic deterministic dynamics. These equilibria are stationary and have absolutely continuous stationary measures. We prove that they can be learned by a simple rule based on the histograms of past state variables. This work gives a theoretical justification for complex deterministic models that might compete with stochastic models to explain real data. Also we prove the stochastic stability of the indeterminate equilibrium.     

Environmental sustainability, nonlinear dynamics and chaos

Summary. This paper studies the possibility of nonlinear dynamics in a simple overlapping generations model with the environment – the John-Pecchenino (1994) model. We show that if people's concerns towards greener preferences and the maintenance efficiency relative to degradation are not sufficiently high, cyclically or chaotically fluctuating equilibria are more likely to exist; moreover, under a specific condition, a complicated topological structure might emerge. Our short-run analysis complements John and Pecchenino's long-run analysis and our findings suggest that the associated transition towards an environmentally sustainable state is not trivial. Received: September 10, 1996; revised version: October 2, 1997     

Diversity, persistence and chaos in consumption patterns

In this paper we present a model from which discretionary consumption dynamics can be analyzed as global properties emerging from the endogenous transformation of a society inhabited by boundedly rational interactive consumers. By considering local and global interactions among consumers, we show that behavioral diversity plays a central role in the evolution of consumption patterns. The analysis of the model reveals the existence of a regime characterized by the persistence of different social standards, and a time evolution of the social distribution of behavioral patterns towards a heteroclinic cycle. In some cases the evolution seems to be chaotic, generating unpredictable, erratic dynamics of the aggregate social indices (average or social propensity for discretionary consumption).      

Schumpeterian growth,chaos, and the formation of dissipative structures

This paper reformulates several basic ideas introduced by Joseph Schumpeter to examine the correlation between productivity growth and technological change in order to explore why American productivity growth has been sluggish for the past two decades. Convetional growth theory maintains that a primary cause of low productivity growth is inadequate capital formation, which in turn is caused by low private domestic saving. This paper borrows concepts from cybernetics, formal information theory, and chaotic dynamic systems to describe the Schumpeterian process through which innovative “new combinations” of capital goods generate wealth, productivity increases, and income growth, and which in turn cause increased savings. It describes the process through which such fundamental technological changes are diffused by entrepreneurs throughout the economy, and concludes that the fundamental causes of America's relatively weak productivity growth are to be found in policies or practices that inhibit innovation and entrepreneurship.     

Structural break,nonlinearity and asymmetry: a re-examination of PPP proposition

In this study, we examine the validity of the PPP proposition for 28 European countries. For this purpose, we propose a new unit root test procedure that allows for both gradual structural breaks and asymmetric nonlinear adjustment towards the equilibrium level. Small-sample properties of the new tests are examined through Monte-Carlo simulations. The simulation results suggest that the new tests have satisfactory size and power properties. We then apply these new tests along with other unit root tests to examine stationarity properties of real exchange rate series of the sample countries. Our tests reject the null of unit root in more cases when compared to alternative tests. Overall, we find that the PPP proposition holds in majority of the European countries examined in this article.     

Uncertainty, Commitment, and Optimal Taxation

This paper examines the optimal tax design problem in the presence of wage uncertainty. The wage has a continuous distribution, individuals are ex ante identical, preferences are separable in labor supply and goods, public policy aims at providing the population with social insurance, and the only restriction on the tax instruments is that emanating from lack of public observability of realized wages and labor supplies. We show that optimal tax structures depend crucially on whether it is labor supply or goods that consumers have to commit to before the resolution of uncertainty. Specifically, we prove that, in the absence of commitment, the social insurance problem collapses to the traditional optimal tax problem. Second, if labor supply is precommitted, it would be possible to effect a first-best outcome. Third, commitment to goods would make indirect taxation a useful instrument of tax policy even in the presence of a general income tax; it requires differential tax treatment of committed and noncommitted goods. Finally, if preferences are separable between the two types of goods, precommitted goods must be taxed at a uniform rate lower than that on the noncommitted goods.     

Heterogeneity,social esteem and feasibility of collective action

In the presence of individual heterogeneity, a major problem with egalitarian partnership, such as complete income pooling, is that individuals of comparatively high ability are induced to exit the arrangement. This is nevertheless ignoring the possible impact of social esteem considerations based on a comparison of members' performances. In this paper, drawing inspiration from pooling experiences in a Japanese fishery, we show that the exit problem can be surmounted if sensitivity to social esteem is neither too strong nor too weak. If it is too strong, the lower ability agents will exit out of social shame whereas, if it is too weak, the higher ability agents will not consider it worthwhile to transfer income to their partners. When the arrangement is sustainable, the lower ability people strive towards limiting the income gap.     

Optimal search,learning and implementation

We characterize the incentive compatible, constrained efficient policy (“second-best”) in a dynamic matching environment, where impatient, privately informed agents arrive over time, and where the designer gradually learns about the distribution of agents? values. We also derive conditions on the learning process ensuring that the complete-information, dynamically efficient allocation of resources (“first-best”) is incentive compatible. Our analysis reveals and exploits close, formal relations between the problem of ensuring implementable allocation rules in our dynamic allocation problems with incomplete information and learning, and between the classical problem, posed by Rothschild (1974) [20], of finding optimal stopping policies for search that are characterized by a reservation price property.     

Foreign capital,dependence, destabilisation and feasibility of transition to socialism

The paper analyses the argument that external capital inflow could create dependence and thus sabotage the possibility of a successful transition to socialism. The formal model deployed is of the Harrod-Domar variety and simulation run are undertaken for five underdeveloped countries, using savings functions estimated by Weisskopf. The conclusions lend some support to radical concerns about the adverse effects of foreign aid on recipient countries.     

Optimal fiscal policy, uncertainty, and growth

This paper analyzes the macroeconomic effects of fiscal policy in a stochastic endogenous growth model. Due to externalities in human capital accumulation, the market allocation is inefficient, thereby justifying government intervention. The uncertainty stemming from technological disturbances affects the growth rate, which can be explained by precautionary motives of risk averse agents. Fiscal policy means consist of a consumption tax, investment subsidies, and bonds. We obtain counter-acting growth effects of investment subsidies, which are differentiated with respect to deterministic and stochastic capital income components. The policy implications from the deterministic model are substantially extended in the stochastic context. A general rule for a welfare maximizing policy is derived, which is represented by a continuum of alternative tax-transfer-schemes. We discuss three benchmark cases, which crucially differ with respect to their implications regarding the size of the government expenditure share.     

Environment, Asset Characteristics, and Optimal Effluent Fees

This article investigates theissue of optimal effluent fees in a frameworkwhere waste emissions are abated by investingin capital of which the pay-off is uncertainand the cost is fully sunk. The stock of wasteemissions harms an individual firm'sproduction, but the firm will underestimatethis external effect upon investing. Consequently, the firm will invest lesscapital, and thereby, pollute more than issocially desirable. The regulator, who can useeffluent fees to correct this, should imposelower effluent fees on irreversible investmentsthan on costlessly reversible ones whenuncertainty arises.     

Microstructure Noise, Realized Variance, and Optimal Sampling

A recent and extensive literature has pioneered the summing of squared observed intra-daily returns, "realized variance", to estimate the daily integrated variance of financial asset prices, a traditional object of economic interest. We show that, in the presence of market microstructure noise, realized variance does not identify the daily integrated variance of the frictionless equilibrium price. However, we demonstrate that the noise-induced bias at very high sampling frequencies can be appropriately traded off with the variance reduction obtained by high-frequency sampling and derive a mean-squared-error (MSE) optimal sampling theory for the purpose of integrated variance estimation. We show how our theory naturally leads to an identification procedure, which allows us to recover the moments of the unobserved noise; this procedure may be useful in other applications. Finally, using the profits obtained by option traders on the basis of alternative variance forecasts as our economic metric, we find that explicit optimization of realized variance's finite sample MSE properties results in accurate forecasts and considerable economic gains.     

Nonlinear Pricing, Redistribution, and Optimal Tax Policy

This paper examines the role of nonlinear pricing by public (or regulated) utilities as a redistributive mechanism in presence of an optimal nonlinear income tax. It models an economy with many types of persons who differ in two unobservable characteristics (earning abilities and tastes). We show that nonlinear pricing does have a redistributive role; it is not a substitute for an ill-designed tax policy. We prove, assuming separable preferences, that a person whose valuation of the public sector output is smaller than the average valuation of the population (all measured at the same consumption bundle) must face a marginal price for the good above its marginal cost. Further assuming that tastes and earning abilities are perfectly correlated, we prove that everyone must face a marginal price for the public sector's output which strictly exceeds its marginal cost if correlation is positive. These properties provide an economic rationale for the provision of "support for low-income consumers" as mandated by the universal service and similar regulatory policies. Finally, we show that with correlated characteristics, implementation can be achieved through two separate functions: a pricing function that depends only on the public sector output and a tax function that depends only on income.     

Audit Misperception, Tax Compliance, and Optimal Uncertainty

The purpose of this paper is to shed light on the role of taxpayers’ misperceptions in determining compliance behavior. This paper also analyzes the effect of increased randomness on evasion, revenue, and welfare. Whether or not individuals choose to evade taxes depends on the perceived audit probability and on the fraction of honest taxpayers in the population. When individuals know the precise probability of audit, the model becomes in effect a game of coordination, a situation that gives rise to multiple equilibria. This paper incorporates audit misperception by introducing a small amount of uncertainty about the true audit probability. With the introduction of this uncertainty, we verify that there is a unique equilibrium cutoff point, such that each taxpayer evades if and only if his perceived signal falls below this cutoff. It is argued that this unique equilibrium outcome fares better than others in explaining empirical and experimental observations. We also find that, when reducing uncertainty has no cost, the optimal uncertainty is generally indeterminate, even when including zero uncertainty. Finally, we show that, when reducing uncertainty is costly, eliminating all uncertainty can never be optimal. In the limit as this cost vanishes, the optimal uncertainty is unique, meaning that introducing a small amount of enforcement cost resolves the indeterminacy problem.     

Revenge, Tax Informing, and the Optimal Bounty

A common belief is that the IRS pays tax informants 10% of whatever their tips produce in revenue. Actually, the bounty rate is even lower, averaging, in recent years, less than 2% of the amount of taxes and fines recovered. Why is it that the IRS is so tightfisted in rewarding informants who help recover taxes that otherwise would not have been recovered? The present paper approaches this question from an economic perspective, introducing a simple model of the informing decision, the implications of which are incorporated into the tax administration's problem of selecting a bounty rate, as well as a probability of convicting informed‐upon evaders, that maximize its expected net revenues from tax informing. The paper shows that a revenue‐maximizing tax administration would set its bounty rate lower and its prosecution efforts higher, the stronger, at the margin, informants' desire to get revenge on former parties with whom they have quarreled. While the IRS may be guided by ethical and moral considerations in designing its bounty scheme, it nevertheless behaves as if it were cynically exploiting informants' emotional drives, cutting down on their fair share in the recovered amounts to help finance its efforts in prosecuting informed‐upon evaders.     

Search,Concave Production,and Optimal Firm Size

This paper demonstrates that in a free entry search and bargaining economy with concave production firms over-employ. Bargaining allows the worker's wage to depend upon marginal productivity. As such, with strictly concave production, the wage declines as firms employ more labor. Firms react to this declining wage function by choosing an inefficiently large number of workers. However, in equilibrium, fewer firms are likely to enter causing aggregate employment and vacancies to fall.Journal of Economic LiteratureClassification Numbers: J30, J41, J50.     

企业家的最优投资消费与定价

笔者考虑一个面临随机需求风险的企业家,如何通过消费平滑、风险管理及有成本地动态调整资本资产规模,实现消费效用最大化的公司金融问题.笔者运用动态随机控制方法,得到了非完备市场与非风险中性下企业资本的平均价值与边际价值的半闭式解及相应的最优经营策略;基于经典的资本资产定价(CAPM)理论,得到了企业家的期望收益率、企业的贝塔系数和风险溢价.数值结果表明,在非完备市场下企业家的风险态度对企业资本价值、贝塔系数、风险溢价、企业家的期望收益率及相应的最优经营策略等都具有显著影响.     

Optimal retirement age,leisure and consumption

In this paper, we study the determination of optimal retirement age, optimal leisure time, and optimal consumption, and we also analyze their relationships using an optimal control theory. We establish a life cycle model and analyze the factors of consumption, leisure, saving, mortality and retirement behaviors simultaneously with an orthogonal-array experimental design. Our results show that the initial salary level and the growth rate of salary are the most important determining factors of the optimal retirement age. The initial consumption level and the interest rate are also important factors affecting optimal retirement age. The mortality improvement has a minor effect on the optimal retirement age. The effects of the Social Security on the optimal retirement age depend on the Social Security tax and the level of Social Security benefit.     

Real interest rates: nonlinearity and structural breaks

Real interest rate is a crucial variable that determines the consumption, investment and saving behavior of individuals and thereby acts as a key policy tool that the central banks use to control the economy. Although many important theoretical models require the real interest rates to be stationary, the empirical evidence accumulated so far has not been able to provide conclusive evidence on the mean reverting dynamics of this variable. To resolve this puzzle we re-investigate the stochastic nature of the real interest rates by developing unit root tests for nonlinear heterogeneous panels where the alternative hypothesis allows for a smooth transition between deterministic linear trends around which stationary asymmetric adjustment may occur. When the newly developed panel unit root tests are applied to the real interest rates of the 17 OECD countries, we were able to uncover overwhelming empirical support in favor of mean reversion in the short-run and long-run real interest rates. Therefore, these results show that the conclusions drawn from a miss-specified test that ignores the presence of either nonlinearity, structural breaks or cross sectional dependence can give quite misleading results about the stochastic behavior of the real interest rates.