Inflation Targeting, Credibility and Confidence Crises

We study the interplay between the central bank transparency, its credibility, and the inflation target level. Based on a model developed in the spirit of the global games literature, we argue that whenever a weak central bank adopts a high degree of transparency and a low target level, a bad and self confirmed type of equilibrium may arise. In this case, an over-the-target inflation becomes more likely. The central bank is considered weak when favorable state of nature is required for the target to be achieved. On the other hand, if a weak central bank opts for less ambitious goals, namely lower degree of transparency and higher target level, it may avoid confidence crises and ensure a unique equilibrium for the expected inflation. Moreover, even after ruling out the possibility of confidence crises, less ambitious goals may be desirable in order to attain higher credibility and hence a better coordination of expectations. Conversely, a low target level and a high central bank transparency are desirable whenever the economy has strong fundamentals and the target can be fulfilled in many states of nature.

The trade-off between incentives and endogenous risk

Standard models of moral hazard predict a negative relationship between risk and incentives, but the empirical work has not confirmed this prediction. In this paper, we propose a model with adverse selection followed by moral hazard, where effort and the degree of risk aversion are private information of an agent who can control the mean and the variance of profits. For a given contract, more risk-averse agents supply more effort in risk reduction. If the marginal utility of incentives decreases with risk aversion, more risk-averse agents prefer lower-incentive contracts; thus, in the optimal contract, incentives are positively correlated with endogenous risk. In contrast, if risk aversion is high enough, the possibility of reduction in risk makes the marginal utility of incentives increasing in risk aversion and, in this case, risk and incentives are negatively related.Incentives, non-monotone contracts, single-crossing property.

The trade-off between incentives and endogenous risk

Standard models of moral hazard predict a negative relationship between risk and incentives, but the empirical work has not confirmed this prediction. In this paper, we propose a model with adverse selection followed by moral hazard, where effort and the degree of risk aversion are private information of an agent who can control the mean and the variance of profits. For a given contract, more risk-averse agents supply more effort in risk reduction. If the marginal utility of incentives decreases with risk aversion, more risk-averse agents prefer lower-incentive contracts; thus, in the optimal contract, incentives are positively correlated with endogenous risk. In contrast, if risk aversion is high enough, the possibility of reduction in risk makes the marginal utility of incentives increasing in risk aversion and, in this case, risk and incentives are negatively relatedIncentives, non-monotone contracts, single-crossing property.

Speculative Attacks on Debts and Optimum Currency Area: A Welfare Analysis

Resorting to an extension of the debt crisis model of Cole and Kehoe (JIE 1996), we evaluate financial aspects of an optimum currency area. Our focus is to appraise the welfare of a country, which belongs to a monetary union and might suffer a speculative attack on its public debt. A default may be avoided by an inflation tax on common-currency debt, but this decision depends on majority voting and have costs associated with it. Moreover, the model considers symmetry between national and central governments' decisions about inflation and also describes the loss in international bankers' confidence towards one country being passed on to another. One of our results is that, for a country with low weight in the voting system, common-currency regime is superior in terms of expected welfare to dollarization and may be a better choice than the local-currency one, as the central bank under the latter regime undergoes some political influence from its government.

Pure strategy equilibria of single and double auctions with interdependent values

We prove the existence of monotonic pure strategy equilibrium for many types of asymmetric auctions with n bidders and unitary demands, interdependent values and independent types. The assumptions require monotonicity only in the own bidder's type. The payments can be a function of all bids. Thus, we provide a new equilibrium existence result for asymmetrical double auctions and a small number of bidders. The generality of our setting requires the use of special tie-breaking rules. We present a reasonable counterexample for interdependent values auctions that shows that sometimes all equilibria are trivial, that is, they have zero probability of trade. Nevertheless, we give sufficient conditions for non-trivial equilibrium existence

PURE STRATEGY EQUILIBRIA OF SINGLE AND DOUBLE AUCTIONS WITH INTERDEPENDENT VALUES

We prove the existence of monotonic pure strategy equilibrium for many types of asymmetric auctions with n bidders and unitary demands, interdependent values and independent types. The assumptions require monotonicity only in the own bidder's type. The payments can be a function of all bids. Thus, we provide a new equilibrium existence result for asymmetrical double auctions and a small number of bidders. The generality of our setting requires the use of special tie-breaking rules. We present a reasonable counterexample for interdependent values auctions that shows that sometimes all equilibria are trivial, that is, they have zero probability of trade. Nevertheless, we give sufficient conditions for non-trivial equilibrium existence.

As Leis de Falência: uma Abordagem Econômica

Our goal in this paper is to study the Bankruptcy Laws under the approach of the Economic Theory. In this sense, we present some suggestions of the recent literature and study the convenience of their practical use. We also show, through numerical examples, how to obtain a Pareto improvement by choosing the proper punishment level to be adopted in the case of economic agents bankruptcy.

Non-monotoniticies and the all-pay auction tie-breaking rule

Discontinuous games, such as auctions, may require special tie-breaking rules to guarantee equilibrium existence. The best results available ensure equilibrium existence only in mixed strategy with endogenously defined tie-breaking rules and communication of private information. We show that an all-pay auction tie-breaking rule is sufficient for the existence of pure strategy equilibrium in a class of auctions. The rule is explicitly defined and does not require communication of private information. We also characterize when special tie-breaking rules are really needed

Pure Strategy Equilibria of Multidimensional and Non-Monotonic Auctions

We give necessary and sufficient conditions for the existence of symmetric equilibrium without ties in common values auctions, with multidimensional independent types and no monotonic assumptions. When the conditions are not satisfied, we are still able to prove the existence of pure strategy equilibrium with an exogenous and explicit tie breaking mechanism. As a basis for these results, we obtain a characterization lemma that is valid under a general setting, that includes non-independent types, asymmetrical utilities and any attitude towards risk. Such characterization gives a basis for an intuitive interpretation for the behavior of the bidder: to bid in order to equalize the marginal benefit and the marginal cost of biddingauctions, pure strategy equilibria, non-monotonic bidding functions, tie-breaking

Endogenous Collateral

We study an economy where there are two types of assets. Consumers' promises are the primitive defaultable assets secured by collateral chosen by the consumers themselves. The purchase of these personalized assets by ¯- nancial intermediaries is ¯nanced by selling back derivatives to consumers. We show that nonarbitrage prices of primitive assets are strict submartin- gales, whereas nonarbitrage prices of derivatives are supermartingales. Next we establish existence of equilibrium, without imposing bounds on short sales. The nonconvexity of the budget set is overcome by considering a continuum of agentsEndogenous collateral