Constrained Pseudo-Market Equilibrium

We propose a pseudo-market solution to resource allocation problems subject to constraints. Our treatment of constraints is general: including bihierarchical constraints due to considerations of diversity in school choice, or scheduling in course allocation; and other forms of constraints needed to model, for example, the market for roommates, combinatorial assignment problems, and knapsack constraints. Constraints give rise to pecuniary externalities, which are internalized via prices. Agents pay to the extent that their purchases affect the value the of relevant constraints at equilibrium prices. The result is a constrained-efficient market-equilibrium outcome. The outcome is fair to the extent that constraints treat agents symmetrically. (JEL D47, D61, D63, I11, I21)

Costs of Sales Forces, Substitution between Competing Products, and Vertical Integration Decisions

This paper analyzes duopolistic firms’ vertical integration decisions with considering costs of sales forces and sales delegation under vertical integration. The main contribution of our research is showing that full vertical integration (separation) is more common when competing products are highly (weakly) substitutable. Second, contrary to conventional wisdom, an asymmetric vertical structure may not only be an equilibrium outcome but may also be optimal for consumers’ surplus in spite of yielding higher retail prices than those arising under full vertical integration. We also examine the impacts of vertical structures on welfare which have vertical merger policy relevance. First, when products are weakly substitutable, keeping vertical merger costs low may induce full vertical integration to be an equilibrium outcome which optimizes consumers’ surplus and social welfare simultaneously. Second, imposing a vertical merger tax increasing with substitution between products on firms may induce firms’ vertical integration decisions to be optimal for social welfare.

Entry-Proofness and Discriminatory Pricing under Adverse Selection

This paper studies competitive allocations under adverse selection. We first provide a general necessary and sufficient condition for entry on an inactive market to be unprofitable. We then use this result to characterize, for an active market, a unique budget-balanced allocation implemented by a market tariff making additional trades with an entrant unprofitable. Motivated by the recursive structure of this allocation, we finally show that it emerges as the essentially unique equilibrium outcome of a discriminatory ascending auction. These results yield sharp predictions for competitive nonexclusive markets. (JEL D11, D43, D82, D86)

Policy Experimentation in Committees: A Case against Veto Rights under Redistributive Constraints

We study optimal policy experimentation by a committee. We consider a dynamic bargaining game in which committee members choose either a risky reform or a safe alternative each period. When no redistribution is allowed, the unique equilibrium outcome is generically inefficient. When redistribution is allowed (even small amounts), there always exists an equilibrium that supports optimal experimentation for any voting rule without veto players. With veto players, however, optimal policy experimentation is possible only with a sufficient amount of redistribution. We conclude that veto rights are more of an obstacle to optimal policy experimentation than are the constraints on redistribution themselves. (JEL D72, C78, H23, D78, D71)

Equilibrium Tax Rates under Ex-ante Heterogeneity and Income-dependent Voting

The standard models with incomplete markets (e.g. Aiyagari) have difficulty justifying the current income tax rates as an optimal or political equilibrium outcome. Given the highly skewed income distribution, the majority of the population would be in favor of raising taxes to a much higher level. We show that incorporating (i) the ex-ante heterogeneity of earnings and (ii) income-dependent voting behavior helps us to reconcile the large gap between the model and data.

Behavior and the Transmission of COVID-19

A simple model of COVID-19 that incorporates feedback from disease prevalence to disease transmission through an endogenous response of human behavior does a remarkable job fitting the main features of the data on the growth rates of daily deaths observed across a large number of countries and states in the United States in 2020. This finding, however, suggests a new empirical puzzle: very large wedges that shift disease transmission rates holding disease prevalence fixed are required both across regions and within a region over time for the model to match the data on deaths from COVID-19 as an equilibrium outcome exactly.

Fees, Reputation, and Information Production in the Credit Rating Industry

We compare a credit rating agency’s incentives to acquire costly information when it is only paid for giving favorable ratings to the corresponding incentives when the agency is paid up-front, i.e., irrespective of the ratings assigned. We show that, in the presence of moral hazard, contingent fees provide stronger dynamic incentives to acquire information than up-front fees and may induce higher social welfare. When the fee structure is chosen by the agency, contingent fees arise as an equilibrium outcome, in line with the way the market for credit rating actually works. (JEL D21, D82, D83, G24)

Those who can't sort, steal: caste, occupational mobility, and rent-seeking in rural India

Three important features of Indian labor markets enduringly coexist: rent-seeking, occupational immobility, and caste. These facts are puzzling, given theories that predict static, equilibrium social inequality without conflict. Our model explains these facts as an equilibrium outcome. Some people switch caste-associated occupations for an easier source of rents, rather than for productivity. This undermines trust between castes and shuts down occupational mobility, which further encourages rent-seeking due to an inability of workers to sort into occupations. We motivate our contribution with novel stylized facts exploiting a unique survey question on casteism in India, which we show is associated with rent-seeking.

Duopoly price competition with limited capacity

We study a variation of the duopoly model by Kreps and Scheinkman (1983). Firms limited by their capacity of production engage in a two stage game. In the first stage they commit to levels of production not exceeding their capacities which are then made common knowledge. In the second stage after production has taken place firms simultane- ously compete in prices. Solution of this sequential game shows that the unique Cournot equilibrium outcome as in Kreps and Scheinkman is not always guaranteed. However the Cournot outcome is still robust in the sense that given sufficiently large capacities this equilibrium holds. If capacities are sufficiently small, firms decide to produce at their full capacity and set a price which clears the market at the given level of output.