Educação e investimentos externos como determinantes do crescimento a longo prazo

Esse artigo usa uma metodologia de decomposição tendência-ciclo para estimar o produto potencial brasileiro e investigar a importância relativa dos choques permanentes e transitórios. Conclui-se que os primeiros explicam quase que 100% da variância do produto privado. A partir desta evidência, investiga-se a existência de relações de longo prazo entre o produto potencial e diversos possiveis determinantes do crescimento a longo prazo, como investimentos externos, escolaridade média e taxa de analfabetismo da população econolTÚcamente ativa. Conclui-se que as duas primeiras possuem uma relação de longo prazo com o produto potencial, e que a elasticidade de longo prazo é não desprezível. A luz desta evidência, discute-se questões de política econômica.

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 suppIy more effort in risk reduction. If the marginal utility of incentives decreases with risk aversion, more risk-averse agents prefer lower-incentive contractsj 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.

Nonparametric specification tests for conditional duration models

This paper deals with the testing of autoregressive conditional duration (ACD) models by gauging the distance between the parametric density and hazard rate functions implied by the duration process and their non-parametric estimates. We derive the asymptotic justification using the functional delta method for fixed and gamma kernels, and then investigate the finite-sample properties through Monte Carlo simulations. Although our tests display some size distortion, bootstrapping suffices to correct the size without compromising their excellent power. We show the practical usefulness of such testing procedures for the estimation of intraday volatility patterns.

Dinâmica não-linear e sustentabilidade da dívida pública brasileira

This paper contributes to the debate on whether the Brazilian public debt is sustainable or not in the long run by considering threshold effects on the Brazilian Budget Deficit. Using data from 1947 to 1999 and a threshold autoregressive model, we find evidence of delays in fiscal stabilization. As suggested in Alesina (1991), delayed stabilizations reflect the existence of political constraints blocking deficit cuts, which are relaxed only when the budget deficit reaches a sufficiently high level, deemed to be unsustainable. In particular, our results suggest that, in the absence of seignorage, only when the increase in the budget deficit reaches 1.74% of the GDP will fiscal authorities intervene to reduce the deficit. If seignorage is allowed, the threshold increases to 2.2%, suggesting that seignorage makes government more tolerant to fiscal imbalances.

Trade liberalization and industrial concentration: evidence from Brazil

This paper applies an endogenous lobby formation model to explain the extent of trade protection granted to Brazilian manufacturing industries during the 1988- 1994 trade liberalization episode. Using a panel data set covering this period, we find that even in an environment in which a major regime shift has been introduced, more concentrated sectors have been able to obtain policy advantages, that lead to a reduction in international competition. The importance of industry structure appears to be substantial: In our baseline specification, an increase in concentration by 20% leads to an increase in protection by 5%-7%.

Collateral, default penalties and almost finite-time solvency

We argue that it is possible to adapt the approach of imposing restrictions on available plans through finitely effective debt constraints, introduced by Levine and Zame (1996), to encompass models with default and collateral. Along this line, we introduce in the setting of Araujo, Páscoa and Torres-Martínez (2002) and Páscoa and Seghir (2008) the concept of almost finite-time solvency. We show that the conditions imposed in these two papers to rule out Ponzi schemes implicitly restrict actions to be almost finite-time solvent. We define the notion of equilibrium with almost finite-time solvency and look on sufficient conditions for its existence. Assuming a mild assumption on default penalties, namely that agents are myopic with respect to default penalties, we prove that existence is guaranteed (and Ponzi schemes are ruled out) when actions are restricted to be almost finite-time solvent. The proof is very simple and intuitive. In particular, the main existence results in Araujo et al. (2002) and Páscoa and Seghir (2008) are simple corollaries of our existence result.

Preferences, common knowledge and speculative trade

We study the proposition that if it is common knowledge that en allocation of assets is ex-ante pareto efficient, there is no further trade generated by new information. The key to this result is that the information partitions and other characteristics of the agents must be common knowledge and that contracts, or asset markets, must be complete. It does not depend on learning, on 'lemons' problems, nor on agreement regarding beliefs and the interpretation of information. The only requirement on preferences is state-additivity; in particular, traders need not be risk-averse. We also prove the converse result that "no-trade results" imply that traders' preferences can be represented by state-additive utility functions. We analyze why examples of other widely studied preferences (e.g., Schmeidler (1989)) allow "speculative" trade.

O método generalizado dos momentos (MGM): conceitos básicos

O presente texto desenvolve, com fins didáticos, as propriedades básicas do Método Generalizado dos Momentos (MGM). Faz parte de obra (livro) em elaboração.