Knowledge that Transforms

Many countries use college-major-specific admissions policies that require a student to choose a college-major pair jointly. Given the potential of student-major mismatches, we explore the equilibrium effects of postponing student choice of major. We develop a sorting equilibrium model under the college-major-specific admissions regime, allowing for match uncertainty and peer effects. We estimate the model using Chilean data. We introduce the counterfactual regime as a Stackelberg game in which a social planner chooses college-specific admissions policies and students make enrollment decisions, learn about their fits to various majors before choosing one. Our estimates indicate that switching from the baseline to the counterfactual regime leads to a 1% increase in average student welfare and that it is more likely to benefit female, low-income and/or low-ability students.

We study the effects of securitization on interbank lending competition. An applicant's observable features are seen by a remote bank, while her true credit quality is known only to a local bank. Without securitization, the remote bank does not compete because of a winner's curse. With securitization, in contrast, ignorance is bliss: the less a bank knows about its loans, the less of a lemons problem it faces in selling them. This enables the remote bank to compete successfully in the lending market. Consistent with the empirical evidence, remote and securitized loans default more than observationally equivalent local and unsecuritized loans, respectively.

Abstract. This paper studies the following problem. An agent takes actions based on a possibly misspecified model. The agent is large, in the sense that his actions influence the model he is trying to learn about. The agent is aware of potential model misspecification and tries to detect it, in real-time, using an econometric specification test. If his model fails the test, he formulates a new better-fitting model. If his model passes the test, he uses it to formulate and implement a policy based on the provisional assumption that the current model is correctly specified, and will not change in the future. We claim that this testing and model validation process is an accurate description of most macroeconomic policy problems. Unfortunately, the dynamics produced by this process are not at all well understood. We make progress on this problem by relating it to a problem that is well understood. In particular, we relate it to the dynamics of constant-gain stochastic approximation algorithms. Doing this enables us to appeal to well known results from the large deviations literature to help us understand the dynamics of testing and model revision. We show that as the agent applies an increasingly stringent specification test, the large deviation properties of the discrete model validation dynamics converge to those of the continuous learning dynamics. This sheds new light on the recent constant-gain learning literature. JEL Classification Numbers: C120, E590 1.

We argue that one major cause of the U.S. post-war baby boom was the rise in female labour supply during World War II. We develop a quantitative dynamic general equilibrium model with endogenous fertility and female labour force participation decisions. We use the model to assess the impact of the war on female labour supply and fertility in the decades following the war. For the war generation of women, the high demand for female labour brought about by mobilization leads to an increase in labour supply that persists after the war. As a result, younger women who reach adulthood in the 1950s face increased labour market competition, which impels them to exit the labour market and start having children earlier. The effect is amplified by the rise in taxes necessary to pay down wartime government debt. In our calibrated model, the war generates a substantial baby boom followed by a baby bust.

A dynamic model with credit under limited commitment is constructed, in which limited memory can weaken the effects of punishment for default. This creates an endogenous role for government debt in credit markets, and the economy can be non-Ricardian. Default can occur in equilibrium, and government debt essentially plays a role as collateral and thus improves borrowers' incentives. The provision of government debt acts to discourage default, whether default occurs in equilibrium or not.

We study the mechanism design problem of guaranteeing desirable performances whenever agents are rational in the sense of not playing weakly dominated strategies. We first provide an upper bound for the best performance we can guarantee among all feasible mechanisms. The bound is represented as the maximized value of the designer's objective subject to the inequality version of the standard envelope incentive conditions. We then prove the bound to be tight under certain conditions on the designer's prior over the agents' pay-off types in auction and bilateral-trade applications. In private-value auction and bilateral trade, the optimal mechanisms (a second-price auction and posted-price mechanism, respectively) satisfy dominant-strategy incentive compatibility, the classical notion of "robust" mechanisms. In an interdependent-value auction, we find that a second-price auction is optimal in revenue with interdependent values, which is neither dominant-strategy nor ex post incentive compatible, but satisfies the novel incentive compatibility introduced in this analysis.

An important line of research using laboratory experiments has provided a new potential reason for gender imbalances in labour markets: men are more competitively inclined than women. Whether, and to what extent, gender differences in attitudes toward competition lead to differences in naturally occurring labour markets remains an open question. To examine this, we run a natural field experiment on job-entry decisions where we randomize almost 9000 job-seekers into different compensation regimes. By varying the role that individual competition plays in setting the wage and the gender composition, we examine whether a competitive compensation regime, by itself, can cause differential job entry. The data highlight the power of the compensation regime in that women disproportionately shy away from competitive work settings. Yet, there are important factors that attenuate the gender differences, including whether the job is performed in teams, whether the position has overt gender associations, and the age of the job-seekers. We also find that the effect is most pronounced in labour markets with attractive alternative employment options. Furthermore, our results suggest that preferences over uncertainty can be just as important as preferences over competition per se in driving job-entry choices.