Are Co-integrated Stock Prices Consistent with the Efficient Market Hypothesis?

This paper responds to the unsatisfactory argument that there is no correspondence between co-integration and the efficient market hypothesis. A law of one co-integrating vector of prices is proposed for the exchange rate and domestic and overseas stock prices. Markets must therefore be efficient in long-run equilibrium because no arbitrage opportunities exist. However, arbitrage activity via the disequilibrium error correction allows above-average (risk-adjusted) returns to be earned in the short run. The elimination of these arbitrage opportunities means that stock market inefficiency in the short run ensures stock market efficiency in the long run.     

Production, trade, prices, exchange rates and equilibration in large experimental economies

We study market equilibration in laboratory economies that are larger and more complex than any that have been studied experimentally to date. Complexity is derived from the fact that the economies are “international” in economic structure with multiple input, output, and foreign exchange markets in operation. The economies have twenty-one markets and due to the fact that they have roughly fifty agents, the economies are characterized by several hundred equations. In spite of the complexity and interdependence of the economy, the results demonstrate the substantial power of the general equilibrium model of perfect competition to predict the direction of movement of market-level variables. Empirical patterns in the convergence process are explored and described.     

Income distribution, borrowing constraints and redistributive policies

This paper sheds light on the relationship between income inequality and redistributive policies and provides possible guidance in the specification of empirical tests of such a relationship. We model a two-period economy where capital markets are imperfect and agents vote over the level of taxation to finance redistributive policies that enhance future productivity. In this context, we show that the pivotal voter is not necessarily the agent (class) with median income. In particular, the poor, who are more likely to be liquidity constrained, may form a coalition with the rich and vote for low redistribution. The effects of an increase in income inequality on the level of redistribution turn out to depend on whether the increase in inequality is concentrated among the poor or the middle class. Empirical results from a panel of 22 OECD countries provide preliminary evidence consistent with our main theoretical implications.     

A note on cheap talk and burned money

Austen-Smith and Banks [Cheap talk and burned money, J. Econ. Theory 91(1) (2000) 1-16] study how money burning can expand the set of pure cheap talk equilibria of Crawford and Sobel [Strategic information transmission, Econometrica 50(6) (1982) 1431-1451]. I identify an error in the main Theorem of Austen-Smith and Banks, and provide a variant that preserves some of the important implications. I also prove that cheap talk can be influential with money burning if and only if it can be influential without money burning. This strengthens a result of Austen-Smith and Banks, but uncovers other errors in their analysis. Finally, an open conjecture of theirs is proved correct.     

Irreversible investment and Knightian uncertainty

When firms make a decision about irreversible investment, they may not have complete confidence about their perceived probability measure describing future uncertainty. They may think other probability measures perturbed from the original one are also possible. Such uncertainty, characterized by not a single probability measure but a set of probability measures, is called “Knightian uncertainty.” The effect of Knightian uncertainty on the value of irreversible investment opportunity is shown to be drastically different from that of traditional uncertainty in the form of risk. Specifically, an increase in Knightian uncertainty decreases the value of investment opportunity while an increase in risk increases it.     

Nonlinearities and heterogeneity in environmental quality: An empirical analysis of deforestation

We use a panel data set of 59 developing countries over the 1972–1994 period to study the deforestation process. Relying on both parametric and semiparametric models, we examine nonlinearities and heterogeneity in the deforestation process. We first study the existence of an Environmental Kuznets Curve (EKC) and then analyze determinants of deforestation. Our data sample provides no evidence of an EKC. We also find that political institution failures may worsen the deforestation process in developing countries.     

Stable matchings and preferences of couples

Couples looking for jobs in the same labor market may cause instabilities. We determine a natural preference domain, the domain of weakly responsive preferences, that guarantees stability. Under a restricted unemployment aversion condition we show that this domain is maximal for the existence of stable matchings. We illustrate how small deviations from (weak) responsiveness, that model the wish of couples to be closer together, cause instability, even when we use a weaker stability notion that excludes myopic blocking. Our remaining results deal with various properties of the set of stable matchings for “responsive couples markets”, viz., optimality, filled positions, and manipulation.     

Unilateral production restrictions in a dynamic duopoly

This paper examines a dynamic game of exploitation of a productive asset by a duopoly. A closed-loop Nash equilibrium of the game is constructed and used to analyze the effects of a unilateral production restriction. Surprisingly, such unilateral action may result in a decrease of the long-run asset's stock. We also exhibit production restrictions that can result simultaneously in an increase of the asset's stock and the long-run profits of the firm that is being imposed the production restriction. Moreover, a unilateral decrease of the production of one firm can induce its rival to also decrease its production.     

Inflation, investment and economic performance: The role of internal financing

This paper studies a link between inflation and economic activity that is built on two hypotheses. First, firms mitigate informational frictions in financial markets by accumulating retained earnings over a period of time. Second, firms allocate earnings among three competing uses - dividends, current investment, and the accumulation of internal funds - and inflation directly distorts this allocation decision as well as the real value of accumulated internal funds. The model predicts that the level of inflation - both unanticipated and expected inflation - as well as the variability of inflation distort firms’ internal financing decisions, increases frictions in financial markets, reduces the level and efficiency of investment, and reduces aggregate output. The marginal effects of inflation are increasing in the inflation rate.     

Equilibrium binding agreements: a comment

To construct their Equilibrium Binding Agreements, Ray and Vohra (J. Econ. Theory, 73 (1997) 30-78) define a concept of an equilibrium between coalitions and prove its existence for any coalition structure. We show that this result crucially depends on the quasi-concavity of the utility functions, which in turn depends on the type of mixed strategies used by the coalitions. When coalitions use uncorrelated mixed strategies utility functions may not be quasi-concave and an equilibrium may not exist. However, if coalitions use correlated strategies, an equilibrium always exist.