Working papers results

We study the competitive equilibria in a market with adverse selection and search frictions. Uninformed buyers post general direct mechanisms and informed sellers choose where to direct their search. We demonstrate that there exists a unique equilibrium allocation and characterize its properties: all buyers post the same mechanism and a low quality object is traded whenever such object is present in a meeting. Sellers are thus pooled at the search stage and screened at the mechanism stage. If adverse selection is sufficiently severe, this equilibrium is constrained inefficient. Furthermore, the properties of the equilibrium differ starkly from the case where meetings are restricted to be bilateral, in which case in equilibrium sellers sort themselves at the search stage across different mechanisms. Compared to such sorting equilibria, our equilibriumyields a higher surplus for most, but not all, parameter specifications.

We propose a flexible Bayesian model averaging method to estimate a factor pricing model characterized by structural uncertainty and instability in factor loadings and idiosyncratic risks. We use such a framework to investigate key differences in the pricing mechanism that applies to residential vs. non-residential real estate investment trusts (REITs). An analysis of cross-sectional mispricings reveals no evidence of a pure hous- ing/residential real estate bubble inflating between 1999 and 2007, to subsequently burst. In fact, all REITs sectors record increasing alphas during this period, and show important differences in the dynamic evolution of risk factor exposures.

Hansen and Richard (1987) prove a classic representation theorem for prices of payoffs in a conditional asset market. In this note we study the portfolio formation and portfolio pricing rules that ensure that the prices of payoffs generated by portfolios actually satisfy the assumptions of their representation theorem. In this way, we obtain a fundamental theorem of finance for conditional asset pricing.

We develop a general equilibrium asset pricing model under incomplete information and rational learning in order to understand the unexplained predictability of option prices. In our model, the fundamental dividend growth rate is unknown and subject to breaks. Immediately after a break, there is insufficient information to price option contracts accurately. However, as new information arrives, a representative Bayesian agent recursively learns about the parameters of the process followed by fundamentals. We show that learning makes beliefs time-varying and generates predictability patterns across option contracts with different strike prices and maturities; as a result, the implied movements in the implied volatility surface resemble those observed empirically.

This paper explores the potential use of entertainment media programs for achieving development goals. I propose a simple framework for interpreting media effects that hinges on three channels: (i) information provision, (ii) role modeling and preference change, and (iii) time use. I then review the existing evidence on how exposure to commercial television and radio affects outcomes such as fertility preferences, gender norms, education, migration and social capital. I complement these individual country studies with cross-country evidence from Africa and with a more in-depth analysis for Nigeria, using the Demographic Health Surveys. I then consider the potential educational role of entertainment media, starting with a discussion of the psychological underpinnings and then reviewing recent rigorous evaluations of edutainment programs. I conclude by highlighting open questions and avenues for future research.

We empirically identify the lending standards applied by banks to small and medium firms over the cycle. We exploit an institutional feature of the Italian credit market that generates a sharp discontinuity in the allocation of comparable firms into credit risk categories. Using loan-level data, we show that during the expansionary phase of the cycle, banks relax lending standards by narrowing the interest rate spreads between substandard and performing firms. During the contractionary phase of the cycle, the abrupt tightening of lending standards leads to the exclusion of substandard firms from credit. These firms then report significantly lower production, investment, and employment. Finally, we find that the drying up of the interbank market is an important factor determining the change in bank lending standards.

We study the effects of a conventional monetary expansion, quantitative easing, and of the maturity extension program on corporate bond yields using impulse response functions to shocks obtained from flexible models with regimes. We construct weekly bond portfolios sorting individual bond trades by rating and maturity from TRACE. A standard single-state VAR model is inadequate to capture the dynamics of the data. On the contrary, under a three-state Markov switching model with time-homogeneous VAR coefficients, we find that unconventional policies may have been generally expected to decrease corporate yields. However, even though the sign of the responses is the one expected by policy-makers, the size of the estimated effects depends on the assumptions regarding the decline in long-term Treasury yields caused by unconventional policies, on which considerable uncertainty remains.

We study monotone, continuous, and quasiconcave functionals defifined over an M-space. We show that if g is also Clarke-Rockafellar differentiable at (see below picture) , then the closure of Greenberg- Pierskalla differentials at x coincides with the closed cone generated by the Clarke-Rockafellar differentials at x. Under the same assumptions, we show that the set of normalized Greenberg-Pierskalla differentials at x coincides with the closure of the set of normalized Clarke-Rockafellar differentials at x. As a corollary, we obtain a differential characterization of quasiconcavity a la Arrow and Enthoven (1961) for Clarke-Rockafellar differentiable functions.

A well functioning bureaucracy can promote prosperity, as advocated by Max Weber. But when bureaucracy gets jammed, it causes stagnation, as described by Franz Kafka. We propose a dynamic theory of the interaction between the production of laws and the efficiency of bureaucracy. When bureaucracy is inefficient the effects of politicians legislative acts are hard to assess. Therefore, incompetent politicians have strong incentives to pass laws to acquire the reputation of skill-full reformers. But too many, often contradictory reforms can in turn lead to a collapse in bureaucratic fficiency. This interaction leads to the existence of both Weberian and Kafkian steady states. A temporary surge in political instability, a strong pressure for reforms by the public, and the appointment of short-lived technocratic governments can determine a permanent shift towards the Kafkian nightmare steady state. Using micro-data for Italy, we provide evidence consistent with one key prediction of the theory: the relative supply of laws by incompetent politicians increases when legislatures are expected to be short.

This paper studies how voters optimally allocate costly attention in a model of probabilistic voting. The equilibrium solves a modified social planning problem that reflects voters' choice of attention. Voters are more attentive when their stakes are higher, when their cost of information is lower and prior uncertainty is higher. We explore the implications of this in a variety of applications. In equilibrium, extremist voters are more influential and public goods are under-provided. The analysis also yields predictions about the equilibrium pattern of information, and about policy divergence by two opportunistic candidates. Endogenous attention can lead to multiple equilibria, explaining how poor voters in developing countries can be politically empowered by welfare programs.