Knowledge that Transforms

In practice one does not expect conflicting agents to move instantaneously to an equilibrium. Instead the final equilibrium is often the consequence of "disequilibrium dynamics". This paper, through the use of local game theory, introduces a general framework for disequilibrium dynamics based on the existence of adjustment costs. The analysis is presented within the context of oligopoly theory and shows that the existence of adjustment costs will in many cases result in a unique equilibrium at which market shares are inversely proportional to these costs. This paper also introduces two new solution concepts for n-person normal form games.

Earlier studies of labour supply in a life cycle context have typically either neglected taxes completely, or represented the income tax by a linear function. The present paper studies how the qualitative conclusions of a “traditional” life cycle model of labour supply are changed when a nonlinear tax is introduced into the model. It is shown that the comparative statics results, and the characterization of the consumption and labour supply paths, depend critically on whether capital and labour income are taxed jointly or separately, and on the progressivity (nonlinearity) of the income tax. Few of the results valid for a linear income tax carry over to the nonlinear case.

This paper establishes necessary and sufficient conditions for the approximate efficiency of Cournot equilibria in large markets. The analysis is carried out in the partial equilibrium framework of a market for a homogeneous commodity.

Cowell has shown that if an inequality measure satisfies (1) additivity, (2) decomposability (among population groups), (3) additivitiy of the group inequality measures, (4) symmetry within groups, and (5) twice differentiability, it can be written as an additive function of group measures belonging to the CES class or of the form ∑i, si, ln si, where si is the i-th person's share. Using a result from the theory of functional equations, I prove that the first two conditions, often imposed for analytical convenience, alone imply Cowell's structure. Symmetry, or other ethical postulates, can then be represented by simple parametric restrictions.

Singularity of the transition matrix in differential equation systems implies indeterminacy of the stationary equilibrium: we show that this indeterminacy is only apparent, and we provide the unique solution. There are many examples of, and good theoretical reasons for, singular transition matrices. The main result is that, when stability conditions arc satisfied, the resulting stationary equilibrium will depend upon the intial conditions and the parameters describing the speed of adjustment.

In the late 1970s, countries in Latin America's Southern Cone initiated attempts to lower domestic inflation rates through the progressive reduction of a preannounced rate of exchange-rate devaluation. The stabilization programs gave rise to massive capital inflows, real exchange-rate appreciation, and current-account deficits. This paper develops a stylized intertemporal framework in which the effects of a credible preannounced disinflation scheme can be studied. It is shown that even when agents have perfect foresight and markets clear continuously, the "capital inflows" phenomenon and the associated real appreciation may result. While unanticipated, permanent inflation changes are neutral in the paper, anticipated inflation is neutral only in exceptional circumstances. A preannounced disinflation operates by altering the path of an expenditure-based real domestic interest rate that depends on expected changes in the prices of liquidity services and nontradable consumption goods.

A procedure of sliding planning is considered in a simple dynamic model of Leontief type. At every step of this procedure, a long-term plan is generated starting from a current state of the economy for a future time interval of a fixed finite length (a “forecast horizon”), but only a decision concerning the first year is implemented. Proceeding from the attained state, the next step is carried out. Matrices of input-output coefficients are assumed to vary within uniform bounds. Provided that the forecast horizon is sufficiently long, the resulting sliding planning path is proved to be in a certain sense approximately optimal.

Dominant strategies seldom exist in non-cooperative games. Moulin's concept of a dominance solvable game generalizes, dominant strategy without dramatic loss in appeal. We consider a class of common-value auctions characterized by the property that the maximum of a collection of informative signals is a sufficient statistic for the entire collection. We demonstrate that this class of second-price auctions is dominance solvable.

Recent work on macroeconomics of price increases of intermediate imports while theoretically rigorous and elegant, is still unable to explain the stylized facts. This paper attempts to remedy the shortcomings of earlier papers by using a two-period model to properly analyse investment and savings behaviour and hence the current account. The model also incorporates disequilibrium in first-period labour and goods markets to compare the response of countries in different disequilibrium regimes to shocks in intermediate input prices.

We prove the existence of general economic equilibrium under uncertainty when agents form econometric models of the relationship among their private information, prices, and the state of the environment. The functional form of each agent's model is specified in advance, with a finite number of parameters to be determined. Agents are then thought of as performing linear least squares estimation of the parameters. Equilibrium requires not only that markets clear, but also that each agent be using the vector of parameter values which, within a compact convex set of parameters, gives the least squares best fit to the data that is generated by the working of the economy when agents adhere to their models.