Full-cost pricing in the classical competitive process: A model of convergence to long-run equilibrium

In the last 10–15 years a lot of attempts has been devoted to study the calssical process of convergence of market prices toward natural prices. The two forces that one has thought could achieve this target were capital mobility, that determines the dynamics of output, and demand-supply forces, that determine the dynamics of prices. In this article a model of classical competition is proposed in which a full-cost pricing mechanism is adopted in the rule of evolution of market prices. An asymptotical stability result of long-run equilibrium is proved for a two-commodity model with and without a final demand.     

Moral hazard and Marshallian inefficiency: Evidence from Tunisia

We formalize the link between optimal cost-sharing contracts and the production technology in the presence of moral hazard by appealing to several well-known results from duality theory. Building on intuitions from the interlinkage literature, we show that optimal contractual structure is determined by the (i) substitution possibilities that exist between different observable factor inputs, as well as (ii) between these inputs and unobservable effort. We endogenize contractual choice using landlord characteristics as instruments, exploiting the fact that, in our dataset, landlords interact with several tenants and vice versa. The approach is applied to an unbalanced plot-level panel of cost-sharing contracts in a Tunisian village, using a translog representation of the restricted profit function. Contractual terms are found to be a significant determinant of input use and therefore lead to Marshallian inefficiency, while the optimality of the underlying contractual structure is rejected.     

On the impact of leverage constraints on asset prices and trading volume

Abstract. Researchers have used stylized facts on asset prices and trading volume in stock markets (in particular, the mean reversion of asset returns and the correlations between trading volume, price changes and price levels) to support theories where agents are not rational expected utility maximizers. This paper shows that this empirical evidence is in fact consistent with a standard infinite horizon – perfect information – expected utility economy where some agents face leverage constraints similar to those found in todays financial markets. In addition, and in sharp contrast to the theories above, we explain some qualitative differences that are observed in the price-volume relation on stock and on futures markets. We consider a continuous-time economy where agents maximize the integral of their discounted utility from consumption under both budget and leverage constraints. Building on the work by Vila and Zariphopoulou (1997), we find a closed form solution, up to a negative constant, for the equilibrium prices and demands in the region of the state space where the constraint is non-binding. We show that, at the equilibrium, stock holdings volatility as well as its ratio to stock price volatility are increasing functions of the stock price and interpret this finding in terms of the price-volume relation. We would like to thank the editor and two anonimous referees for valuable substantive comments. Our gratitude also to Franklin Allen, Kerry Back, Domenico Cuoco, Xavier Freixas, Sanford Grossman, Michel Habib, Lutz Hendricks, Richard Kihlstrom, Fernando Restoy, Mary Thomson, Jean-Luc Vila, participants to seminars at Birkbeck College, Carnegie-Mellon, Columbia, ESSEC, HEC, IAE, INSEAD, London Business School, London School of Economics, McGill, Michigan, National University of Singapore, Pompeu Fabra, North Carolina, Washington-St-Louis, Wharton, the Jornadas de Economía Financiera BBV, and the Meetings of the Society for Economic Dynamics and Control and the American Finance Association. Special thanks are due to Süleyman Basak for his enthusiastic support and many helpful suggestions. The usual disclaimer applies. We gratefully acknowledge the support of the BBV and Caja de Madrid Foundations and CREF (both authors) and of the Spanish Ministry of Education under DGICYT grant no. PB93-0388 (first author).     

Critical factors in computing externalities for electricity resources

The New York State Environmental Externalities Cost Study and computerized externality model (EXMOD) are used to examine the specification of methods design and application factors in the computation of electricity externalities. We report the sensitivity of externality estimates with alternative specifications for 15 different factors in the analysis, including the selection of facility type, site, and operating characteristics; air emission assumptions and air modeling procedures; dose-response assumptions; economic valuation assumptions; and other modeling procedures and assumptions. Many of the factors that most influence externality computations can be well specified in the analysis, such as the facility type, age, characteristics, emission rates, whether there is SO₂ trading, and the inclusion of long range impacts. Most significant among the factors for which there remains significant scientific uncertainty are the selection and application of air dispersion models, selection of air pollution thresholds for health impacts, reduced life span risks associated with ozone exposure and with long-term exposure to PM₁₀, values for CO₂ damages, and the value to be applied to increased risks of reduced life span for individuals age 65 or older.     

Short-memory equilibrium in stochastic overlapping generations economies

In stochastic OLG exchange economies, we show that short-memory equilibria—the natural extension from deterministic economies of steady states, low-order cycles, or finite state-space stationary sunspots equilibria—fail to exist generically in utilities. As a result, even with independent and identically distributed exogenous shocks there is serial correlation in endogenous economic variables in equilibrium. This arises even if utilities are time-separable, some goods inferior, and there are no technological lags. Hence, the origins of economic fluctuations can be traced only to the demographic structure of a heterogeneous agent, multiple-good economy.     

Private R&;D and Spillovers in European Agriculture

The objective of this paper is to present econometric evidence of the effects of economic incentives, public policies, and institutions on national aggregate private agricultural R&D investments. The main hypothesis we will test in this paper is whether agricultural R&D spillovers represent a disincentive for national private R&D. More specifically, we will test if the spillovers function, which is a determinant of private R&D, follows a quadratic form and if private R&D is determined by the role of incentives and institutions.A previous draft of this paper was presented at the 57th International Atlantic Economic Conference, Lisbon, Portugal, 10–14 March 2004. Comments from participants have been very useful to improve the paper.     

Nonlinear incentive provision in Walrasian markets: a Cournot convergence approach

The paper studies insurance with moral hazard in a system of contingent-claims markets. Insurance buyers are modelled as Cournot monopolists or oligopolists. The other agents condition their expectations on market prices, as in models of rational-expectations equilibrium with asymmetric information. Thereby they correctly anticipate accident probabilities corresponding to effort incentives induced by insurance buyers’ net trades. When there are many agents to share the insurance buyers’ risks, Cournot equilibrium outcomes are close to being second-best. In contrast, if insurance buyers are price takers, equilibria fail to exist or are bounded away from being second-best.     

A complete characterization of Pareto optimality for general OLG economies

In the context of general pure exchange OLG economies where agents can have heterogeneous longevities, we provide both sufficient and necessary conditions for Pareto optimality of competitive equilibria. For the case in which all agents live for the same number of periods, we find that these conditions are equivalent. We also find this equivalence when agents can have different lifetimes, but in this case we need to impose particular restrictions on relative equilibrium prices. Moreover, we show that without these conditions on prices the equivalence, and hence a full characterization, is not necessarily obtained.     

Price and quantity regulation in general equilibrium

We consider a general equilibrium model with a production externality (e.g. pollution), where the regulator does not observe firm productivity shocks. We examine quantity (permit) regulation and price (tax) regulation. The quantity of permits issued by the regulator are independent of the productivity shock, since shocks are unobserved. Price regulation implies use of the regulated input is an increasing function of the productivity shock because firms take advantage of a good productivity shock by increasing input use. Thus price regulation generates higher average, but more variable, production. Therefore, we show that in general equilibrium the relative advantage of quantity versus price regulation depends not only on the slopes of marginal benefits and costs, but on general equilibrium effects such as risk aversion. The general equilibrium effects are often more important than the slopes of the marginal benefits and cost curves. In the simplest model, a reasonable risk aversion coefficient implies quantity regulation generates higher welfare regardless of the benefit function.     

Stationary solution to the overlapping generations model of fiat money: Experimental evidence

Overlapping generations model of fiat money yields an infinity of competitive equilibrium solutions, only one of which is stationary. Economies reported in this paper involved a sequence of overlapping generations of three or four individuals; each individual lived for two periods. In their young age individuals were endowed with chips that could be traded for fiat money wish the individuals of the old generation. In their old age, individuals could exchange their units o flat money for the consumption good. Results of the experiments exhibit some support for the stationary solution. The results are robust to two designs of exchange institutions (double oral auctior and supply schedule auction) and to two different endogenous ways of converting money into chips at the end of the game (average price prevailing during the last period the game is actually played and the average price forecast made during the last period the game is actually played).A preliminary version of this paper was presented at the meeting of the Economic Science Association and at the Federal Reserve Bank of Minneapolis. The authors are grateful for comments received from various participants at both presentations. Financial support was provided by the McKnight Foundation, the Honeywell Foundation, National Science Foundation (SES 89-12552), and Richard. M. and Margaret Cyert Family Funds.