We show that there is a unique correlated equilibrium, identical to the unique Nash equilibrium, in the classic Bertrand oligopoly model with homogeneous goods and identical marginal costs. This provides a theoretical underpinning for the so-called “Bertrand paradox” as well as its most...

We show that there is a unique correlated equilibrium, identical to the unique Nash equilibrium, in the classic Bertrand oligopoly model with homogenous goods. This provides a theoretical underpinning for the so-called "Bertrand paradox" and also generalizes earlier results on mixed-strategy...

We use an evolutionary model to simulate agents who choose between two options with stochastically varying payoffs. Two types of agents are considered: individual learners, who rely on trial-and-error methods, and social learners, who imitate the wealthiest sampled individual. Agents adapt to...

We provide a modeling framework to think about selective contracting in the health care sector. Two health care providers differ in quality and costs. When buying health insurance, consumers observe neither provider quality nor costs. We derive an equilibrium where health insurers signal...

What are the welfare effects of a policy that facilitates for insurance customers to privately and covertly learn about their accident risks? We endogenize the information structure in Stiglitz's classic monopoly insurance model. We first show that his results are robust: For a small information...

We study a monopoly insurance model with endogenous information acquisition. Through a continuous effort choice, consumers can determine the precision of a privately observed signal that is informative about their accident risk. The equilibrium effort is, depending on parameter values, either...

What are the welfare effects of a policy that facilitates for insurance customers to privately and covertly learn about their accident risks? We endogenize the information structure in Stiglitz's classic monopoly insurance model. We first show that his results are robust: For a small information...

If doctors take the costs of treatment into account when prescribing medication, their objectives differ from their patients' objectives because the patients are insured. This misalignment of interests hampers communication between patient and doctor. Giving cost incentives to doctors increases...

We provide a modeling framework to think about selective contracting in the health care sector. Two health care providers differ in quality and costs. When buying health insurance, consumers observe neither provider quality nor costs. We derive an equilibrium where health insurers signal...

Standard insurance models predict that people with high (health) risks have high insurance coverage. It is empirically documented that people with high income have lower health risks and are better insured. We show that income differences between risk types lead to a violation of single crossing...