Although economists have long been interested in the implications of Marshallian externalities (i.e., industry-level external economies of scale) for trading economies, the large number of equilibria that they typically imply has kept such externalities out of the recent quantitative trade...

Conventional analysis in the trade-industrial-organization literature suggests that, when a country has some market power over an imported good, some small level of protection must be welfare improving. This is essentially a terms-of-trade argument that is reinforced if the imported goods are...

There are two principal theories of why countries or regions trade: comparative advantage and increasing returns to scale. Yet there is virtually no empirical work that assesses the relative importance of these two theories in accounting for production structure and trade. We use a framework...

Increasing returns are as fundamental a cause of international trade as comparative advantage, but their role has until recently been neglected because of the problem of modelling market structure. Recently substantial theoretical progress has been made using three different approaches. These...

Because of scale effects, idea-based growth models have the counterfactual implication that larger countries should be much richer than smaller ones. New trade models share this same problematic feature: although small countries gain more from trade than large ones, this is not strong enough to...

A large empirical literature found that the correlation between insurance purchase and ex post realization of risk is often statistically insignificant or negative. This is inconsistent with the predictions from the classic models of insurance a la Akerlof (1970), Pauly (1974) and Rothschild and...

We study the Rothschild-Stiglitz model of competitive insurance markets with endogenous information disclosure by both firms and consumers. We show that an equilibrium always exists, (even without the single crossing property), and characterize the unique equilibrium allocation. With two types...

Across a wide set of non-group insurance markets, applicants are rejected based on observable, often high-risk, characteristics. This paper argues private information, held by the potential applicant pool, explains rejections. I formulate this argument by developing and testing a model in which...

We study the effect of the life settlement market on the structure of long term contracts offered by the primary market for life insurance, as well as the effect on consumer welfare, using a dynamic model of life insurance with one sided commitment and bequest-driven lapsation. We show that the...

This paper reviews and evaluates the empirical literature on adverse selection in insurance markets. We focus on empirical work that seeks to test the basic coverage-risk prediction of adverse selection theory--that is, that policyholders who purchase more insurance coverage tend to be riskier....