Empirical measures,learning and sunspot equilibrium

In this paper we construct sunspot equilibria that arrise from chaotic deterministic dynamics. These equilibria are robust and therefore observables. We prove that they may be learned by a sim pie rule based on the histograms or past state variables. This work gives the theoretical justification or deterministic models that might compete with stochastic models to explain real data.

Demand-pull stagflation

This paper explores the possibility of stagflation emanating exc1usively from monetaJy sbocks, without concurrent supply shocks or shifts in potential output. This arises in connection with a tight money paradox. in the context of a fiscal theory of the price leveI. The paper exhibits perfect foresight equilibria with output and inflation fluctuating in opposite direetions as a consequence of small monetary shocks, and also following changes in monetaJy policy regime that launch the economy into hyperinflation or that produce dramatic stabilization of already high inflation. For that purpose, an analytically convenient dynamic general equilibrium macro model is deve10ped wbere nominal rigidities are represented by a cross between staggered two-period contracts and state dependent price adjustment in the presence of menu costs.

Sequential auctions with continuation costs

In actual sequential auctions, 1) bidders typically incur a cost in continuing from one sale to the next, and 2) bidders decide whether or not to continue. To investigate the question "when do bidders drop out," we define a sequential auction model with continuation costs and an endogenously determined number of bidders at each sale, and we characterize the equilibria in this modele Simple examples illustrate the effect of several possible changes to this modele

Discrete public goods with incomplete information

We analyze simultaneous discrete public good games with incomplete information and continuous contributions. To use the tenninology of Admati and Perry (1991), we consider contribution and subscription games. In the former, contributions are not refunded ifthe project is not completed, while in the latter they are. For the special case where provision by a single player is possible we show the existence of an equihbrium in both contnbution and subscription games where a player decides to provide the good by himself. For the case where is not feasible for a single player to provide the good by himself: we show that there exist equilibria of the subscription game where each participant pays the same amount. Moreover, using the technical apparatus from Myerson (1981) we show that neither the subscription nor the contribution games admit ex-post eÁ cient equibbria. hl addition. we provide a suÁ cient condition for êontributing zero 'to be the unique equihbrium of the contnbution game with n players.

An economic model of gun control

Guns stolen from law-abiding households provide the principal source of guns for criminals. The lethality of crime instruments increases with the availability of guns, so the gun market is subject to externalities that generate excessive ownership and inadequate spending on protective measures to deter gun theft. One motive for gun ownership is self defense, and the gun market is subject to coordination failure: the more guns purchased lawfully, the more will be stolen by criminals, so the greater the incentive for lawful . consumers to purchase guns for self defense. As a result, there may be multiple equilibria in the gun market and more than one equilibrium crime rate. We show that a simple refundable deposit for guns will internalize the externalities in the gun market and may cause large downward jumps in gun ownership, the lethality of crime instruments, and the social costs of crime.

Valuation equilibrium with crubs

This paper considers model worlds in which there are a continuum of individuaIs who form finite sized associations to undertake joint activities. We show that if there are a finite set of types and the commodity space contains lotteries, then the c1assicaI equilibrium results on convex economies can be reinterpreted to apply. Furthermore, in this lottery economy deterministic aIlocations (that is, degenerate lotteries) are generally not Pareto optimal, nor are they equilibria. In the interests of making the model seem more "natural," we show that the set of equilibria in a decentraIization in which individuaIs first gamble over vaIue transfers and then trade commodities in a deterministic competitive market economy are equivalent to those of our competi tive economy with a lottery commodity space.

A notion of subgame perfect nash equilibrium under knightian uncertainty

We define a subgame perfect Nash equilibrium under Knightian uncertainty for two players, by means of a recursive backward induction procedure. We prove an extension of the Zermelo-von Neumann-Kuhn Theorem for games of perfect information, i. e., that the recursive procedure generates a Nash equilibrium under uncertainty (Dow and Werlang(1994)) of the whole game. We apply the notion for two well known games: the chain store and the centipede. On the one hand, we show that subgame perfection under Knightian uncertainty explains the chain store paradox in a one shot version. On the other hand, we show that subgame perfection under uncertainty does not account for the leaving behavior observed in the centipede game. This is in contrast to Dow, Orioli and Werlang(1996) where we explain by means of Nash equilibria under uncertainty (but not subgame perfect) the experiments of McKelvey and Palfrey(1992). Finally, we show that there may be nontrivial subgame perfect equilibria under uncertainty in more complex extensive form games, as in the case of the finitely repeated prisoner's dilemma, which accounts for cooperation in early stages of the game .

Political budget cycles in a fiscal federation : the effect of partisan voluntary transfers

This article first presents an econometric study suggesting that intergovernmental transfers to Brazilian municipalities are strongly partisan motivated. In light of that stylized fact, it develops an extension to Rogoff (1990)’s model to analyze the effect of partisan motivated transfers into sub-national electoral and fiscal equilibria. The main finding is that important partisan transfers may undo the positive selection aspect of political budget cycles. Indeed, partisan transfers may, on one hand, eliminate the political budget cycle, solving a moral hazard problem, but, on the other hand, they may retain an incompetent incumbent in office, bringing about an adverse selection problem.

Two heads may not be better than one : corporate board structure, managerial self-dealing,and common agency

This paper compares the effects on corporate performance and managerial self-dealing in a situation in which the CEO reports to a single Board that is responsible for both monitoring management and establishing performance targets to an alternative in which the CEO reports to two Boards, each responsible for a different task. The equilibrium set of the common agency game induced by the dual board structure is fully characterized. Compared to a single board, a dual board demands less aggressive performance targets from the CEO, but exerts more monitoring. A consequence of the first feature is that the CEO always exerts less effort toward production with a dual board. The effect of a dual board on CEO self-dealing is ambiguous: there are equilibria in which, in spite of the higher monitoring, self-dealing is higher in a dual system. The model indicates that the strategic interdependence generated by the assignment of different tasks to different boards may yield results that are far from the desired ones.

Sovereign debt with adverse selection : a quantitative approach

We construct a dynamic equilibrium model to quantitatively study sovereign debt with contingent services and country risk spreads such that the benefits of defaulting are tempered by higher interest rates in the future. For a wide range of parameters, the only equilibrium of the model is one in which the sovereign defaults in all states, unless defaulting incurs additional costs. Due to the adverse selection problem, some countries choose to delay default in order to reduce reputation loss. Although equilibria with no default imply in greater welfare levels, they are not sustainable in the highly indebted and volatile countries.

Common agency with informed principals

We analyze a common agency game under asymmetric information on the preferences of the non-cooperating principals. Asymmetric information introduces incentive compatibility constraints which rationalize the requirement of truthfulness made in the earlier literature on common agency games under complete information. There exists a large class of differentiable equilibria which are ex post inefficient and exhibit free-riding. We then characterize some interim efficient equilibria. Finally, there exists also a unique equilibrium allocation which is robust to random perturbations. This focal equilibrium is characterized for any distribution of types.

O conjunto dos equilíbrios dos leilões de primeiro preço

In this note I specify the class of functions that are equilibria of symmetric first-price auctions.

Phase transition of demand explained by the heterogeneity of consumers' intrinsic preferences

In 1991 Gary S. Becker presented A Note on Restaurant Pricing and Other Examples of Social In uences on Price explaining why many successful restaurants, plays, sporting events, and other activities do not raise their prices even with persistent excess demand. The main reason for this is due to the discontinuity of stable demands, which is explained in Becker's (1991) analysis. In the present paper we construct a discrete time stochastic model of socially interacting consumers deciding for one of two establishments. With this model we show that the discontinuity of stable demands, proposed by Gary S. Becker, depends crucially on an additional factor: the dispersion of the consumers' intrinsic preferences for the establishments.

Payoff interdependence and information externalities

This paper studies entry under information and payoff externalities. We consider a sequential investment game with uncertain payoffs where each firm is endowed with a private signal about profitability. It is shown that both over- and under-investment characterize the equilibria and that under-investment only occurs when investments are complements. Further we find that a reverse informational externality is present.

Inflation targeting, credibility and coordination aspects

There are plenty of economic studies pointing out some requirements, like the inexistence of fiscal dominance, for inflation targeting framework be implemented in successful (credible) way. Essays on how public targets could be used in the absence of such requirements are unusual. In this papel' we appraise how central banks could use inflation targeting before soundness economic fundamentaIs have been achieved. First, based on concise framework, where confidence crises and imperfect information are neglected, we conclude that less ambitious (greater) target for inflation increases the credibility in the precommitment. Optimal target is higher than the one obtained using the Cukierman-Liviatan [7] model, where increasing credibility effect is not considered. Second, extending the model to make confidence crises possible, multiple equilibria solutions becomes possible too. In this case, to set greater targets for inflation may stimulate confidence crises and reduce the policymaker credibility. On the other hand, multiple (bad) equilibria may be avoided. The optimal target depends on the likelihood of each equilibrium be selected. Finally, when perturbing common knowledge uniqueness is restored even considering confidence crises, as in Morris-Shin[ 14]. The first result, i.e. less ambitious target for inflation increases credibility in precommitment, is also recovered. Adding a precise public signal, cOOl'dinated self-fulfilling actions and equilibrium multiplicity may still exist for some lack of common knowledge (as in Angeleto and Weming[l]). In this case, to set greater targets for inflation may stimulate confidence crisis again, reducing the policymaker credibility. From another aspect, multiple (bad) equilibria may be avoided. Optimal policy prescriptions depend on the likelihood of each equilibrium be selected. Results also indicate that more precise public information may open the door for bad equilibrium, contrary to the conventional wisdom that more central oank transparency is always good when considering inflation targeting framework.