Water allocation,crop choice,and priority services

We analyze the problem of allocating irrigation water among heterogeneous farmers when water supply is stochastic. If farmers are risk-neutral, a spot market for water is efficient; while the oft-used uniform rationing system is inefficient, both ex ante and ex post. Indeed, we show that it leads farmers to overexpose to risk, thus making shortages more severe and more frequent in case of drought. We propose instead a regulation by priority classes extending Wilson, and we derive an efficiency result. We characterize the set of farmers that would win or lose from such a reform. We also argue that a system of priority classes may be preferred to a spot market system, because scarcity is easier to manage ex ante than ex post, and because this system facilitates the supply of insurance to risk-averse agents.     

Optimal pricing and capacity choice for a public service under risk of interruption

We develop rules for pricing and capacity choice for an interruptible service that recognize the interdependence between consumers’ perceptions of system reliability and their market behavior. Consumers post ex ante demands, based on their expectations on aggregate demand. Posted demands are met if ex post supply capacity is sufficient. However, if supply is inadequate all ex ante demands are proportionally interrupted. Consumers’ expectations of aggregate demand are assumed to be rational. Under reasonable values for the consumer’s degrees of relative risk aversion and prudence, demand is decreasing in supply reliability. We derive operational expressions for the optimal pricing rule and the capacity expansion rule. We show that the optimal price under uncertainty consists of the optimal price under certainty plus a markup that positively depends on the degrees of relative risk aversion, relative prudence and system reliability. We also show that any reliability enhancing investment—though lowering the operating surplus of the public utility—is socially desirable as long as it covers the cost of investment.     

Regulation,Local Monopolies and Spatial Competition

Many regulated industries involve an oligopoly market structure. We examine optimal incentive regulation for a duopoly model of spatial competition when firms have private cost information. Market structure is endogenous as regulation determines market segments for firms and output distribution across consumers in each firm's market. By varying the assignment of consumers to firms, a relatively more efficient firm can be rewarded with a larger market, thus reducing quantity incentive distortions. We derive the optimal policy, assess the impact of asymmetric information relative to full information, and examine extensions to allow for ex ante asymmetries in firm structure.     

Optimal Liquidity Provision Through a Demand Deposit Scheme: The Jacklin Critique Revisited

We derive conditions such that optimal liquidity provisions through a demand deposit scheme can be sustainably implemented in a subgame perfect Nash equilibrium under the assumption that renegade investors have free access to ex post asset markets. As our qualitative main finding we demonstrate that such sustainability is more likely for ‘poor’ than for ‘rich’ scheme participants in terms of future income. By establishing sustainability for low future income populations, our formal analysis therefore offers an important qualification of Jacklin's (1987) influential claim that an optimal demand deposit scheme is not sustainable whenever there exists the possibility of an ex post asset market.     

Modelling dynamic storage function in commodity markets: Theory and evidence

In this work, we derive a model to investigate the optimal storage policy in metal commodity markets. From an inter-temporal setting, we carry out a criterion driving the stockholding decisions based on Tobin's q rule in which marginal benefits from holding inventories can be compared with marginal storage costs.We estimate the model for the world copper market by taking into account both spot price and convenience yield equations. In our sample, the estimated models are statistically robust and economically coherent with the theory, even though the patterns of the inventory accumulation process show high sensitivity to the uncertainty about worldwide economic conditions.     

Optimal Taxation of Risky Human Capital*

In a two‐period life‐cycle model with ex ante homogeneous households, earnings risk, and a general earnings function, we derive the optimal linear labor tax rate and optimal linear education subsidies. The optimal income tax trades off social insurance against incentives to work. Education subsidies are not used for social insurance, but they are only targeted at offsetting the distortions of the labor tax and internalizing a fiscal externality. Both optimal education subsidies and tax rates increase if labor and education are more complementary, because education subsidies indirectly lower labor tax distortions by stimulating labor supply. Optimal education subsidies (taxes) also correct non‐tax distortions arising from missing insurance markets. Education subsidies internalize a positive (negative) fiscal externality if there is underinvestment (overinvestment) in education because of risk. Education policy unambiguously allows for more social insurance if education is a risky activity. However, if education hedges against labor‐market risk, optimal tax rates could be lower than in the case without education subsidies.     

The empirical content of Cournot competition

We consider the testable implications of the Cournot model of market competition. Our approach is nonparametric in the sense that we abstain from imposing any functional specification on market demand and firm cost functions. We derive necessary and sufficient conditions for (reduced form) equilibrium market price and quantity functions to be consistent with the Cournot model. In addition, we present identification results for the corresponding inverse market demand function and the firm cost functions. Finally, we use our approach to derive testable restrictions for the models of perfect competition, collusion and conjectural variations. This identifies the conditions under which these different models are empirically distinguishable from the Cournot model. We also investigate empirical issues (measurement error and omitted variables) related to bringing our testable restrictions to data.     

Public policies as specification errors

Treating public policies as computable dynamic general equilibrium model specification errors offers computational and conceptional advantages for comparing models with data. The set of policies calculated to rationalize observed behaviors raises the substantive economic question whether, in any particular market, actual public policies sufficiently coincide with the model's behavior-rationalizing policies, or whether the model offers correct hypotheses about the determinants of demand and supply. As illustrations, public policies are calculated to rationalize, with respect to the stochastic neoclassical growth model, capital market behavior since WWII and labor market behavior in 1929–1950. One conclusion is that capital taxation drives a wedge between consumption growth and the expected pre-tax capital return, in the direction and amount predicted by the theory, and that capital taxation is the major intertemporal distortion in the postwar capital market. Second, a good theory of the Great Depression labor market must explain why measured MRS and MPL diverged so dramatically in 1929–1933 and why the wedge persisted.     

Courts of Law and Unforeseen Contingencies

We study a contracting model with unforeseen contingencies inwhich the court is an active player. Ex ante, the contractingparties cannot include the risky unforeseen contingencies inthe contract they draw up. Ex post, the court observes whetheran unforeseen contingency occurred and decides whether to voidor uphold the contract. If the contract is voided by the court,the parties can renegotiate a new agreement ex post. There aretwo effects of a court that voids contracts. The parties' incentivesto undertake relationship-specific investment are reduced, andthe parties enjoy greater insurance against the unforeseen contingenciesthat the ex ante contract cannot account for. In this context,we fully characterize the optimal decision rule for the court.The behavior of the optimal court is determined by the trade-offbetween the need for incentives and the gains from insurancethat voiding in some circumstances offers to the agents.     

Unemployment insurance design: Inducing moving and retraining

Evidence suggests that unemployed individuals can affect their job prospects by undertaking a costly action like deciding to move or retrain. Realistically, such an opportunity only arises for some individuals and the identity of those may be unobservable ex ante. The problem of characterizing constrained optimal unemployment insurance in this case has been neglected in previous literature. We construct a model of optimal unemployment insurance where multiple incentive constraints are easily handled. The model is used to analyze the case when an incentive constraint involving moving costs must be respected in addition to the standard constraint involving costly unobservable job-search. Absent wealth effects on behavior, we derive closed-form solutions showing that when the moving/retraining incentive constraint binds, unemployment benefits should increase over the unemployment spell, with an initial period with low benefits and an increase after this period has expired.     

Access Holidays and the Timing of Infrastructure Investment

For risky infrastructure investment, 'regulatory truncation' can diminish investment incentives. We model the truncation problem, showing the link to regulatory commitment, and derive optimal state-contingent access prices. If regulators cannot commit ex ante to specific ex post access prices then a regulatory commitment to a fixed period free of access – an access holiday – can improve investment incentives. We establish conditions under which an access holiday may improve investment timing and show how an optimal holiday depends on the underlying profit flows from the investment. In particular, we show that an optimal holiday may leave investors with positive expected economic profits.     

The impact of regional and sectoral labor market conditions on wages and labor supply — An empirical analysis for married women using West-German Panel data

In this paper we examine the effects of regional and industry specific labor market indicators on wages and labor supply of married females. Based on the standard life cycle labor supply theory we derive a two equation censored panel model and estimate it using the Minimum Distance Method.For our empirical analysis we use four waves (1984–1987) of West German Panel data merged with regional indicators and industry specific demand side indicators. We obtain the result that, unlike industry specific indicators, regional demand side conditions have virtually no significant effect on market wages but that a direct effect of regional labor market conditions on labour supply remains. We conclude that regional labor market conditions can directly constrain the individual labor supply decision.     

On a Fundamental Advantage of Permits Over Taxes for the Control of Pollution

We extend the tax versus permits literature by considering permit supply functions and pollution tax functions that are generalizations of the usual constant permit supply and constant pollution tax rate. In our model, pollution is not uniformly mixed and the regulator is uncertain about the polluting firms’ abatement costs. We determine the optimal permit supply functions and the optimal pollution tax functions. Using these functions, we show that permits lead unambiguously to lower total expected costs than taxes. We analyze the magnitude of this difference for a simple model of climate change. By relating the optimal permit supply functions to Weitzman (Am Econ Rev 68:683–691, 1978) we provide a new interpretation of his results.     

Export Flexibility And Currency Hedging*

This article studies the behavior of an export‐flexible firm under exchange rate uncertainty. We show that the separation theorem holds if selling exclusively in the domestic market is suboptimal even under the most unfavorable spot exchange rate. Otherwise, the firm's optimal output depends on its preferences and on the underlying uncertainty. We further show that the full‐hedging theorem holds only when the firm always finds it optimal to sell its entire output in the foreign market. Otherwise, export flexibility introduces a convexity into the firm's foreign exchange risk exposure, which calls for the use of currency options for hedging purposes.     

不确定性与早期劳动合同 --契约理论的一个新发展

在劳动力市场上 ,劳动者和厂商未来的生产率都具有不确定性。早期劳动合同或签约由于一方面可以保证劳动者被排除在劳动力市场之外 ,同时也保证了厂商被排除在事后职位市场的风险之外 ,因而厂商和劳动者具有签订早期劳动合同的激励。尽管早期劳动合同或签约存在成本 ,但只要事前利益超过事后无效率的损失 ,那么早期劳动合同或签约就会发生。对于那些不能获得完全市场保险的人来说 ,签约是一种帕累托最优。早期劳动合同或签约是市场失灵的一种证明 ,早期劳动合同是一种不完全合同 ,也是一种非正式合同 ,它是对契约理论的一个发展。     

无就业增长与非均衡劳工市场动态学

本文直接模拟了劳工市场的非均衡过程、工资动态轨迹、经济人的最优行为和适应性优化行为。劳动供给源于家庭的效用最大化 ,劳动需求源于企业的利润最大化。企业的适应性优化行为和若干制度因素构成了工资刚性的基本要素 ,劳工市场的供求力量也是影响工资变动的重要因素。根据劳动生产率的变化对工资进行适应性的调节是现实世界企业工资决策的普遍实践。工资刚性与高劳动生产率并存是造成无就业增长的真正原因     

Using distance functions to understand interest taxation

One of Terence Gorman's insights was that if one wants to derive rules about optimal commodity tax rates (or prices) one should treat quantities consumed as the instruments. This paper builds on Angus Deaton's development of this idea using distance functions. I identify necessary and sufficient conditions for uniform commodity taxation in a static model and the efficiency of various tax structures in a life‐cycle model. One implication is that the optimal interest tax rate may be higher when ordinary or compensated labour supply elasticities are lower.     

Oil supply and economic development strategy: A dynamic planning approach

Most oligopolistic models of the oil market begin with the assumption of rising supply curves for oil. Lack of convincing evidence that high oil prices are being maintained by oligopolistic action has raised the possibility of competitive behavior in the oil market and therefore of a backward bending supply curve. This paper presents numerical solutions of a linear dynamic planning model of an oil exporting country with a development strategy which consists of utilizing oil revenues for building an export sector to replace oil. To make a stronger case a high absorber, Algeria, is used as an example. The numerical results are consistent with the hypothesis that there may well be good economic reasons to restrict supply of oil in response to increased prices. Three important characteristics of the model which produce this result are (a) diminishing marginal utility of consumption, (b) absorptive capacity, and (c) imperfect capital markets. A ‘perverse’ supply behavior is found consistent with optimal allocation of oil resources when a price increase is expected to last for a long time. The effects of temporary price changes which can, for example, result from temporary supply shocks or demand changes during the business cycle are also studied. It is shown that in response to such short term price changes competitive behavior is ‘normal’, i.e., supply varies in the same direction as the price. This implies that reductions in OPEC production which have taken place during the recent market downturns cannot be taken as evidence of cartel coordination, as they usually are, since they are also consistent with price-taking behavior.     

Spot and forward markets for natural gas: The effects of state regulation

Since the emergence of a spot market in natural gas in 1984, state regulators have been concerned that regulated utilities would fail to choose between contracts and spot purchases in a way that minimizes costs. Grounds for this concern are shown, under two alternative rate structures, in a model where regulation produces ex post profit and loss restrictions. Two policy resolutions to the problem are suggested, one that uses an alternative mechanism for triggering rate reviews, allowing the substitution of ex ante for ex post profit and loss restrictions, and one that exploits the special structure of gas markets within the context of traditional regulatory practice.