Knowledge that Transforms

Abstract Should the generosity of unemployment benefits and the progressivity of income taxes depend on the presence of business cycles? This paper proposes a tractable model where there is a role for social insurance against uninsurable shocks to income and unemployment, as well as business cycles that are inefficient due to the presence of matching frictions and nominal rigidities. We derive an augmented Baily–Chetty formula showing that the optimal generosity of the social insurance system depends on a macroeconomic stabilization term. This term pushes for an increase in generosity when the level of economic activity is more responsive to social programmes in recessions than in booms. A calibration to the US economy shows that taking concerns for macroeconomic stabilization into account substantially raises the optimal unemployment insurance replacement rate but has a negligible impact on the optimal progressivity of the income tax. More generally, the role of social insurance programmes as automatic stabilizers affects their optimal design.

Abstract The growth of the “gig” economy generates worker flexibility that, some have speculated, will favour women. We explore this by examining labour supply choices and earnings among more than a million rideshare drivers on Uber in the U.S. We document a roughly 7% gender earnings gap amongst drivers. We show that this gap can be entirely attributed to three factors: experience on the platform (learning-by-doing), preferences and constraints over where to work (driven largely by where drivers live and, to a lesser extent, safety), and preferences for driving speed. We do not find that men and women are differentially affected by a taste for specific hours, a return to within-week work intensity, or customer discrimination. Our results suggest that, in a “gig” economy setting with no gender discrimination and highly flexible labour markets, women’s relatively high opportunity cost of non-paid-work time and gender-based differences in preferences and constraints can sustain a gender pay gap.

Abstract Procuring an innovation involves motivating a research effort to generate a new idea and then implementing that idea efficiently. If research efforts are unverifiable and implementation costs are private information, a trade-off arises between the two objectives. The optimal mechanism resolves the trade-off via two instruments: a cash prize and a follow-on contract. It primarily uses the latter, by favouring the innovator at the implementation stage when the value of the innovation is above a certain threshold and handicapping the innovator when the value of the innovation is below that threshold. A cash prize is employed as a supplementary incentive only when the value of innovation is sufficiently high. These features are consistent with current practices in the procurement of innovation and the management of unsolicited proposals.

Abstract This article develops a search and matching model of mergers and acquisitions (M&A) and uses it to evaluate the implications of merger activity for aggregate economic outcomes. The theory is consistent with a rich set of facts on U.S. M&A, including sorting among merging firms, a substantial merger premium and serial acquisition. It provides a sharp link between these facts and the nature of merger gains. At the micro-level, both complementarities between merging firms and productivity improvements of target firms are important in generating gains. At the macro-level, the model suggests a significant beneficial impact of M&A on aggregate outcomes—the contribution to steady state output is 14% and 4% for consumption—which occurs through the reallocation of resources across firms and equilibrium effects on firm selection and new entrepreneurship. Nevertheless, the economy is not efficient, suggesting a scope for policy improvements—a simple flat tax on M&A can raise steady state consumption as much as 2% relative to the laissez-faire equilibrium. In short, the boundaries of the firm can matter for macroeconomic outcomes.

Abstract In dynamic games, players may observe a deviation from a pre-play, possibly incomplete, non-binding agreement before the game is over. The attempt to rationalize the deviation may lead players to revise their beliefs about the deviator’s behaviour in the continuation of the game. This instance of forward induction reasoning is based on interactive beliefs about not just rationality, but also the compliance with the agreement itself. I study the effects of such rationalization on the self-enforceability of the agreement. Accordingly, outcomes of the game are deemed implementable by some agreement or not. Conclusions depart substantially from what the traditional equilibrium refinements suggest. A non-subgame perfect equilibrium outcome may be induced by a self-enforcing agreement, while a subgame perfect equilibrium outcome may not. The incompleteness of the agreement can be crucial to implement an outcome.

Abstract This article studies equilibrium dynamics in consumer durable goods markets after aggregate credit shocks. We introduce two novel features into a general-equilibrium model of durable consumption with heterogeneous households facing idiosyncratic income risk and borrowing constraints: (1) indivisible durable goods are vertically differentiated in their quality and (2) trade on secondary markets at market-clearing prices, with households endogenously choosing when to trade or scrap their durables. The model highlights a new transmission mechanism for macroeconomic shocks and successfully matches several empirical patterns that we document using data on U.S. car markets around the Great Recession. After a tightening of the borrowing limit, debt-constrained households postpone the decision to scrap and upgrade their low-quality cars, which depresses mid-quality car prices. In turn, this effect reduces wealthy households’ incentives to replace their mid-quality cars with high-quality ones, thereby decreasing new-car sales. We further use our framework to evaluate targeted fiscal stimulus policies such as the Car Allowance Rebate System in 2009 (“Cash for Clunkers”).

Abstract I consider the aggregate impact of low intermediate input intensity in the agricultural sector of developing countries. In a dynamic general equilibrium model with idiosyncratic shocks, incomplete markets, and subsistence requirements, farmers in developing countries use fewer intermediate inputs because it limits their exposure to uninsurable shocks. The calibrated model implies that Indian agricultural productivity would increase by 16% if markets were complete, driven by quantitatively important increases in both the average real intermediate share and measured TFP through lower misallocation. I then extend the results to consider the importance of risk in other contexts. First, the introduction of insurance decreases cross-country differences in agricultural labour productivity by 14%. Second, scaling the introduction of improved seeds to decrease downside risk reduces inequality by reallocating resources from rich to poor farmers via equilibrium effects. This reallocation substantially increases aggregate productivity relative to what would be expected from extrapolating the partial equilibrium impact.