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Working Paper
Intermediation in Networks
I study intermediation in networked markets using a stochastic model of multilateral bargaining in which players compete on different routes through the network. I characterize stationary equilibrium payoffs as the fixed point of a set of intuitive value function equations and study efficiency and the impact of network structure on payoffs. There is never too little trade but there may be an inefficiency through too much trade in states where delay would be efficient. With homogeneous trade surplus the payoffs for players that are not essential to a trade opportunity go to zero as trade ...
Working Paper
Optimal Epidemic Control in Equilibrium with Imperfect Testing and Enforcement
We analyze equilibrium behavior and optimal policy within a Susceptible-Infected-Recovered epidemic model augmented with potentially undiagnosed agents who infer their health status and a social planner with imperfect enforcement of social distancing. We define and prove the existence of a perfect Bayesian Markov competitive equilibrium and contrast it with the efficient allocation subject to the same informational constraints. We identify two externalities, static (individual actions affect current risk of infection) and dynamic (individual actions affect future disease prevalence), and ...
Working Paper
A Model of Charles Ponzi
We develop a model of Ponzi schemes with asymmetric information to study Ponzi frauds. A long-lived agent offers to save on behalf of short-lived agents at a higher rate than they can earn themselves. The long-lived agent may genuinely have a superior savings technology, but may be an imposter trying to steal from short-lived agents. The model identifies when a Ponzi fraud can occur and what interventions can prevent it. A key feature of Ponzi frauds is that the long-lived agent builds trust over time and improves their reputation by keeping the scheme going.
Working Paper
Very Simple Markov-Perfect Industry Dynamics
This paper develops an econometric model of industry dynamics for concentrated markets that can be estimated very quickly from market-level panel data on the number of producers and consumers using a nested fixed-point algorithm. We show that the model has an essentially unique symmetric Markov-perfect equilibrium that can be calculated from the fixed points of a finite sequence of low-dimensional contraction mappings. Our nested fixed point procedure extends Rust's (1987) to account for the observable implications of mixed strategies on survival. We illustrate the model's empirical ...
Working Paper
Very Simple Markov-Perfect Industry Dynamics: Empirics
This paper develops an econometric model of firm entry, competition, and exit in oligopolistic markets. The model has an essentially unique symmetric Markov-perfect equilibrium, which can be computed very quickly. We show that its primitives are identified from market-level data on the number of active firms and demand shifters, and we implement a nested fixed point procedure for its estimation. Estimates from County Business Patterns data on U.S. local cinema markets point to tough local competition. Sunk costs make the industry's transition following a permanent demand shock last 10 to 15 ...
Working Paper
A Model of Charles Ponzi
We develop a model of Ponzi schemes with asymmetric information to study Ponzi frauds. A long-lived agent offers to save on behalf of short-lived agents at a higher rate than they can earn themselves. The long-lived agent may genuinely have a superior savings technology, but may be an imposter trying to steal from short-lived agents. The model identifies when a Ponzi fraud can occur and what interventions can prevent it. A key feature of Ponzi frauds is that the long-lived agent builds trust over time and improves their reputation by keeping the scheme going.
Working Paper
Extended Supplement to “Insurance and Inequality with Persistent Private Information”
This supplement contains auxiliary technical results and proofs omitted from Bloedel, Krishna, and Leukhina (2025) (henceforth BKL) and its Supplemental Appendix (henceforth SA). First, Section I proves parts (a)–(c) and (e)–(f) of Theorem 3 from Appendix B.1 of BKL. (Part (d) of Theorem 3 is proved in SA-E.1 of BKL.) Second, Section J proves Proposition 3.2 from Section 3.3 of BKL and Lemma B.2 from Appendix B.2 of BKL. Finally, Section K proves supporting facts for Properties (a)–(e) from Section 5.2 of BKL. Throughout, we follow the numbering and labeling conventions from BKL and its ...
Working Paper
Insurance and Inequality with Persistent Private Information
This paper studies the optimal tradeoff between insurance and inequality in economies with persistent private information.We consider a principal-agent model in which the principal insures the agent against privately-observed shocks to his endowment, which follows an ergodic finite-state Markov chain that may exhibit arbitrary serial correlation. The optimal contract always induces immiseration: the agent’s consumption and utility become arbitrarily negative in the long run. When the endowment is positively serially correlated, the optimal contract provides increasingly high-powered ...
Working Paper
Insurance and Inequality with Persistent Private Information
This paper studies the implications of optimal insurance provision for long-run welfare and inequality in economies with persistent private information. We consider a model in which a principal insures an agent whose privately observed endowment follows an ergodic, finite Markov chain. The optimal contract always induces immiseration: the agent’s consumption and utility decrease without bound. Under positive serial correlation, the optimal contract also features backloaded high-powered incentives: the sensitivity of the agent’s utility with respect to his report increases without bound. ...
Working Paper
Insurance and Inequality with Persistent Private Information
This paper studies the implications of optimal insurance provision for long-run welfare and inequality in economies with persistent private information. We consider a model in which a principal insures an agent whose privately observed endowment follows an ergodic, finite Markov chain. The optimal contract always induces immiseration: the agent’s consumption and utility decrease without bound. Under positive serial correlation, the optimal contract also features backloaded high-powered incentives: the sensitivity of the agent’s utility with respect to his report increases without bound. ...