Knowledge that Transforms

We consider a general representation of the delegation problem, with and without money burning, and provide sufficient and necessary conditions under which an interval allocation is optimal. We also apply our results to the theory of trade agreements among privately informed governments. For both perfect and monopolistic competition settings, we provide conditions under which tariff caps are optimal. [PUBLICATION ABSTRACT]

We analyze games of incomplete information and offer equilibrium predictions that are valid for, and in this sense robust to, all possible private information structures that the agents may have. The set of outcomes that can arise in equilibrium for some information structure is equal to the set of Bayes correlated equilibria. We completely characterize the set of Bayes correlated equilibria in a class of games with quadratic payoffs and normally distributed uncertainty in terms of restrictions on the first and second moments of the equilibrium action–state distribution. We derive exact bounds on how prior knowledge about the private information refines the set of equilibrium predictions. We consider information sharing among firms under demand uncertainty and find new optimal information policies via the Bayes correlated equilibria. We also reverse the perspective and investigate the identification problem under concerns for robustness to private information. The presence of private information leads to set rather than point identification of the structural parameters of the game.

Belief disagreements have been suggested as a major contributing factor to the recent subprime mortgage crisis. This paper theoretically evaluates this hypothesis. I assume that optimists have limited wealth and take on leverage so as to take positions in line with their beliefs. To have a significant effect on asset prices, they need to borrow from traders with pessimistic beliefs using loans collateralized by the asset itself. Since pessimists do not value the collateral as much as optimists do, they are reluctant to lend, which provides an endogenous constraint on optimists' ability to borrow and to influence asset prices. I demonstrate that the tightness of this constraint depends on the nature of belief disagreements. Optimism concerning the probability of downside states has no or little effect on asset prices because these types of optimism are disciplined by this constraint. Instead, optimism concerning the relative probability of upside states could have significant effects on asset prices. This asymmetric disciplining effect is robust to allowing for short selling because pessimists that borrow the asset face a similar endogenous constraint. These results emphasize that what investors disagree about matters for asset prices, to a greater extent than the level of disagreements. When richer contracts are available, relatively complex contracts that resemble some of the recent financial innovations in the mortgage market endogenously emerge to facilitate betting.

A dynamic structural model of labor supply, welfare participation, and food stamp participation is estimated using the 1992, 1993, and 1996 panels of the Survey of Income and Program Participation. Details of various policies including welfare time limits, work requirements, and Earned Income Tax Credit (EITC) are incorporated formally in the budget constraint. Policy simulations reveal that the economy accounts for half of the increase in the labor supply of female heads of family between 1992 and 1999. A time limit results in a larger efficiency gain than a work requirement or a direct reduction in welfare benefits. A reform package can lead to both a reduction in the government expenditure and an improvement in utility. The EITC expansion results in a substantial efficiency gain among individuals with the lowest expected wage. These individuals are almost unaffected by the economic expansion, but their income and utility increase significantly under the reform package.

In this paper, we propose an instrumental variable approach to constructing confidence sets (CS's) for the true parameter in models defined by conditional moment inequalities/equalities. We show that by properly choosing instrument functions, one can transform conditional moment inequalities/equalities into unconditional ones without losing identification power. Based on the unconditional moment inequalities/equalities, we construct CS's by inverting Cramér–von Mises-type or Kolmogorov–Smirnov-type tests. Critical values are obtained using generalized moment selection (GMS) procedures. We show that the proposed CS's have correct uniform asymptotic coverage probabilities. New methods are required to establish these results because an infinite-dimensional nuisance parameter affects the asymptotic distributions. We show that the tests considered are consistent against all fixed alternatives and typically have power against n−1/2-local alternatives to some, but not all, sequences of distributions in the null hypothesis. Monte Carlo simulations for five different models show that the methods perform well in finite samples.

Different people use language in different ways. We capture this by making language competence—the set of messages an agent can use and understand—private information. Our primary focus is on common-interest games. Communication generally remains possible; it may be severely impaired even with common knowledge that language competence is adequate; and, indeterminacy of meaning, the confounding of payoff-relevant information with information about language competence, is optimal.

This paper studies a dynamic agency problem which includes limited liability, moral hazard, and adverse selection. The paper develops a robust approach to dynamic contracting based on calibrating the incentive properties of simple benchmark contracts that are attractive but infeasible, due to limited liability constraints. The resulting dynamic contracts are detail-free and satisfy robust performance bounds independently of the underlying process for returns, which need not be i.i.d. or even ergodic. [PUBLICATION ABSTRACT]

We propose a new model of flrm reputation that interprets reputation directly as the market belief about product quality. Quality is persistent and is determined endogenously by the flrm’s past investments. We analyse how investment incentives depend on the flrm’s reputation and derive implications for reputational dynamics. We consider three types of consumer learning. When consumers learn about quality through good news, investment incentives are decreasing in reputation, leading to a unique work-shirk equilibrium and convergent dynamics. When consumers learn through bad news, investment incentives are increasing in reputation, leading to a continuum of shirk-work equilibria and divergent dynamics. Finally, when consumers learn through Brownian news and the cost of investment is low, incentives are hump-shaped but a work-shirk equilibrium exists and is essentially unique.

I investigate the role of demand shocks in the ready-mix concrete industry. Using Census data on more than 15,000 plants, I estimate a model of investment and entry in oligopolistic markets. These estimates are used to simulate the effect of eliminating short-term local demand changes. A policy of smoothing the volatility of demand has a market expansion effect: The model predicts a 39% increase in the number of plants in the industry. Since bigger markets have both more plants and larger plants, a demand-smoothing fiscal policy would increase the share of large plants by 20%. Finally, the policy of smoothing demand reduces entry and exit by 25%, but has no effect on the rate at which firms change their size.

This paper investigates the behavior of asset prices in an endowment economy in which a representative agent with power utility consumes the dividends of multiple assets. The assets are Lucas trees; a collection of Lucas trees is a Lucas orchard. The model generates return correlations that vary endogenously, spiking at times of disaster. Since disasters spread across assets, the model generates large risk premia even for assets with stable cashflows. Very small assets may comove endogenously and hence earn positive risk premia even if their cashflows are independent of the rest of the economy. I provide conditions under which the variation in a small asset's price-dividend ratio can be attributed almost entirely to variation in its risk premium.