A study of the impacts of quantitative easing on the macroeconomics variables

Neste trabalho, propusemos um modelo DSGE que busca responder algumas questões sobre políticas de afrouxamento monetário (Quantitative Easing - QE) recentemente implementadas em resposta à crise de 2008. Desenvolvemos um modelo DSGE com agentes heterogêneos e preferred-habitat nas compras de títulos do governo. Nosso modelo permite o estudo da otimalidade da compra de portfolio (em termos de duration dos títulos) para os bancos centrais quando estão implementando a política. Além disso, a estrutura heterogênea nos permite olhar para distribuição de renda provocada pelas compras de títulos. Nossos resultados preliminares evidenciam o efeito distributivo do QE. No entanto, nosso modelo expandido apresentou alguns problemas de estabilidade.

Wald tests for IV regression with weak instruments

This dissertation deals with the problem of making inference when there is weak identification in models of instrumental variables regression. More specifically we are interested in one-sided hypothesis testing for the coefficient of the endogenous variable when the instruments are weak. The focus is on the conditional tests based on likelihood ratio, score and Wald statistics. Theoretical and numerical work shows that the conditional t-test based on the two-stage least square (2SLS) estimator performs well even when instruments are weakly correlated with the endogenous variable. The conditional approach correct uniformly its size and when the population F-statistic is as small as two, its power is near the power envelopes for similar and non-similar tests. This finding is surprising considering the bad performance of the two-sided conditional t-tests found in Andrews, Moreira and Stock (2007). Given this counter intuitive result, we propose novel two-sided t-tests which are approximately unbiased and can perform as well as the conditional likelihood ratio (CLR) test of Moreira (2003).

Contagion and regulation in endogenous bank networks

We develop a simple model of endogenous bank networks to study financial contagion and how leverage regulation may affect it. Banks maximize expected profit by choosing the optimal allocation of resources between three different classes of assets. An interbank network arise as result of loans between banks, creating a direct channel of contagion in the financial system. Contagion may occur when the realized return of the risky asset is sufficiently low to make a bank insolvent, subsequently triggering a cascade effect that propagates through default in interbank loans. Contrary to what would be expected, our results show that despite forcing banks to deleverage, increasing minimum capital requirements may lead to a system with higher aggregate levels of default.

Adverse selection with endogenous entry

Usando como base o ambiente descrito em Moreno e Wooders (2010), neste trabalho, analisamos trocas em um ambiente dinâmico, descentralizado e com seleção adversa. Ao contrário dos autores e da literatura, não consideramos a proporção de ativos de alta qualidade entrantes como independente das características do mercado. Desse modo, adaptamos o modelo dinâmico básico de seleção adversa para incorporar a decisão do vendedor sobre a possibilidade de pagar ou não um preço e transformar seu ativo de baixa qualidade em um ativo de alta qualidade antes de entrar no mercado. E, sob essas condições, mostramos que o bem-estar pode se comportar de maneira diferente do modelo tradicional.

Endogenous normative indices for the industry concentration

This paper presents new indices for measuring the industry concentration. The indices proposed (C n ) are of a normative type because they embody (endogenous) weights matching the market shares of the individual firms to their Marshallian welfare shares. These indices belong to an enlarged class of the Performance Gradient Indexes introduced by Dansby&Willig(I979). The definition of Cn for the consumers allows a new interpretation for the Hirschman-Herfindahl index (H), which can be viewed as a normative index according to particular values of the demand parameters. For homogeneous product industries, Cn equates H for every market distribution if (and only if) the market demand is linear. Whenever the inverse demand curve is convex (concave), H underestimates( overestimates) the industry concentration measured by the normative indexo For these industries, H overestimates (underestimates) the concentration changes caused by market transfers among small firms if the inverse demand curve is convex(concave) and underestimates( overestimates) it when such tranfers benefit a large firm, according to the convexity (or the concavity) of the demand curve. For heterogeneous product industries, an explicit normative index is obtained with a market demand derived from a quasi-linear utilility function. Under symmetric preferences among the goods, the index Cn is always greater than or equal the H-index. Under asymmetric assumptions, discrepancies between the firms' market distribution and the differentiationj substitution distributions among the goods, increase the concentration but make room for some horizontal mergers do reduce it. In particular, a mean preserving spread of the differentiation(substitution) increases(decreases) the concentration only if the smaller firms' goods become more(less) differentiated(substitute) w.r.t. the other goods. One important consequence of these results is that the consumers are benefitted when the smaller firms are producing weak substitute goods, and the larger firms produce strong substitute goods or face demand curves weakly sensitive to their own prices.

Neighborhood feedbacks, endogenous stratification, and income inequality

This paper explores the evolution of the cross-section income distribution in economies where endogenous neighborhood formation interacts with positive within-neighborhood feedback effects. We study an economy in which the economic success of adults is determined by the characteristics of the families in the neighborhood in which a person grows up. These feedbacks take two forms. First, the tax base of a neighborhood affects the leveI of education investment in offspring. Second, the effectiveness of education investment is affected by a neighborhood's in come distribution, reflecting factors such as role model or labor market connection effects. Conditions are developed under which endogenous stratification, defined as the tendency for families wi th similar incomes to choose to form common communities, will occur. When families are allowed to choose their neighborhoods, wealthy families will have an incentive to segregate themselves from the rest of the population. This resulting stratification is supported by house price differences between ricli and poor communities. Endogenous stratification can lead to pronounced intertemporal inequality as different families provide very different interaction environments for offspring. When the transformation of human capital into in come exhibits constant retums to scale, cross-section in come differences may also grow across time. As a result, endogenous stratification and neighborhood feedbacks can interact to produce long run inequality.

On endogenous cost of altruism

The paper extends the cost of altruism model, analyzed in Lisboa (1999). There are three types of agents: households, providers of a service and insurance companies. Households have uncertainty about future leveIs of income. Providers, if hired by a household, have to choose a non-observable leveI of effort, perform a diagnoses and privately learn a signal. For each signal there is a procedure that maximizes the likelihood of the household obtaining the good state of nature. Finally, insurance companies offer contracts to both providers and households. The paper provides suflicient conditions for the existence of equilibrium and shows the optimal contract induces providers to care about their income and also about the likelihood households will obtain the good state of nature, which in Lisboa (1999) was stated as altruism assumption. Equilibrium is inefficient in comparison with the standard moral hazard outcome whenever high leveIs of effort is chosen precisely due to the need to incentive providers to choose the least expensive treatment for some signals. We show, however that an equilibrium is always constrained optimal.

Co-movement between two processes with local persistence

This paper introduces a residual based test where the null hypothesis of c:&InOvement between two processes with local persistenc~ can be tested, even under the presence of an endogenous regressor. It, therefore, fills in an existing lacuna in econometrics, in which longrun relationships can also be tested if the dependent and independent variables do not have a unit root, but do exhibit local persistence.

Endogenous cycles in a Stiglitz-Weiss economy

The literature on financiaI imperfections and business cycles has focused on propagation mechanisms. In this pape r we model apure reversion mechanism, such that the economy may converge to a two period equilibrium cycle. This mechanism confirms that financiaI imperfections may have a dramatic amplification effect. Unlike in some related models, contracts are complete. Indexation is not assumed away. The welfare properties of a possible stabilizing policy are analyzed. The model i tself is a dynamic extension of the well-known Stigli tz-Weiss model of lending under moral hazard. Although stylized the model still captures some important features of credit cycles.

Income composition, endogenous fertility and schooling investments in children

This paper studies how the eomposition of ineome between mothers and fathers affeets fertility and sehooling investments in ehildren, using data from the 1976 and 1996 PNAD, a Brazilian household survey. Ineome composition affeets the time eost of fertility because mothers and fathers alloeate different amounts of time to child-rearing. These effects are in turn transmitted to investments in ehildren through a tradeoffbetween quantity and quality of ehildren. The main contribution of this paper is twofold. First, it derives new implications about the relationship between household ineome composition and schooling investments in ehildren. Seeond, this paper devises and implements an empirieal approaeh to assess these implieations, using two eross-seetions of fertility and schooling data from Brazil. The main empirical findings of the paper ean be summarized as follows. First, the empirical analysis shows that a larger negative effect of the mother's labor in come on fertility in 1996 is associated with a larger positive effect on the adult child's schooling, refleeting the interaction between quantity and quality of children. Second, the larger negative effect of the mother's labor income on fertility in 1996 is associated with a reduction in the effect of other determinants of number of children. This suggests that an increase in the relative importanee of time costs of fertility may be an important determinant of variations in fertility over time in Brazil and other developing countries .

A competitive growth model with endogenous fertility

This paper investigates the interaction between endogenous fertility behavior and the distribution of income and wealth arnong farnilies in a competitive market economy. We construct a growth model in which altruistic dynasties are heterogeneous in their initial stocks of physical capital. Dynasties make choices of farnily size along with decisions about consumption and intergenerational transfers. We show that if the rate of time preference is increasing in the number of children and preferences over nurnber of children satisfy a norrnality assumption, all steady states are characterized by equality of capital stocks and consumption arnong families. We also provide sufficient conditions for uniqueness of the steady state. In order to illustrate these results, we present an example in which preferences over number of children are logarithrnic and the technology is Cobb-Douglas. For this combination of preferences and technology, there exists a unique egalitarian steady state. Moreover, the economy converges to this steady state in only one generation .

Endogenous supply of fiat money

We address whether reputation concerns can discipline the behavior of a self-interested agent who has a monopoly over the provision of fiat money. We obtain that when this agent can commit to a plan of action, there is a monetary equilibrium where it never overissues. We show, however, that such equilibrium is no longer possible when there is no commitment. This happens because the incentives this agent has to maintain a reputation for providing valuable currency disappear once its reputation is high enough. More generally, we prove that there is no monetary equilibrium where overissue happens only infrequently. We conclude by showing that imperfect memory can restore the positive result obtained in the presence of commitment.

Imperfectly credible disinflation under endogenous time-dependent pricing

The real effects of an imperfectly credible disinflation depend critically on the extent of price rigidity. Therefore, the study of how policymakers’ credibility affects the outcome of an announced disinflation should not be dissociated from the analysis of the determinants of the frequency of price adjustments. In this paper we examine how the policymaker’s credibility affects the outcome of an announced disinflation in a model with endogenous time-dependent pricing rules. Both the initial degree of price ridigity, calculated optimally, and, more notably, the changes in contract length during disinflation play an important role in the explanation of the effects of imperfect credibility. We initially evalute the costs of disinflation in a setup where credibility is exogenous, and then allow agents to update beliefs about the “type” of monetary authority that they face. We show that, in both cases, the interaction between the endogeneity of time-dependent rules and imperfect credibility increases the output costs of disinflation.

All-pay auctions with endogenous asymmetries

We study N-bidders, asymmetric all-pay auctions under incomplete information. First, we solve for the equilibrium of a parametric model. Each bidder’s valuation is independently drawn from an uniform [0, αi] where the parameter αi may vary across bidders. In this game, asymmetries are exogenously given. Next, a two-stage game where asymmetries are endogenously generated is studied. At the first stage, each bidder chooses the level of an observable, costly, value-enhancing action. The second stage is the bidding sub-game, whose equilibrium is simply the equilibrium of the, previously analyzed, game with exogenous asymmetries. Finally, natural applications of the all pay-auction in the context of political lobbying are considered: the effects of excluding bidders, as well as, the impact of caps on bids.