Gilad Sorek

Public Health Insurance with Monopolistically Competitive Providers and Optional Spot Sales

Abstract We study the implications of extending public-insurance coverage over differentiated medical products of the same therapeutic group to market outcomes. The public insurer can set the reimbursement level for medical providers and the copayment for the insured for medical care provided under the policy coverage, but cannot directly control providers’ spot sales (outside of insurance) price. In this setup, the price offered by the public insurer to medical providers must maintain their reservation profit from selling on the spot market directly to consumers. We show that the public insurer can manipulate this reservation profit by setting the copayment rate, and thereby promote market welfare while increasing consumers’ surplus due to lower medical prices and lower market entry. The results survive generalizations including moral hazard and incomplete insurance coverage.

Human-capital spillover, population and R&D-based growth

Abstract We study two-sector R&D model with endogenous human capital accumulation. Allowing for fractional human capital spillover from parents to their offspring, which are subject to congestion in fertility rate, we establish non-monotonic relations between population growth and economic growth. These non-monotonic relations, which are polynomial in general, are determined by the base level of human capital spillover and the magnitude of the congestion effect: a U shape relation can arise under low congestion factor, whereas a hump shape may present for high congestion factor. Hence this work contributes to the recent line of modified R&D-based growth models, aimed to align theory with the mixed empirical data on the relation between population growth and economic prosperity.

Reconsidering Copyright: A Spatial Model of Differentiated Competition and Infringement

In practice, copyright is treated by economists and analysts as a tradeoff between monopoly and the incentive to create new works. This tradeoff is between stark opposites – power and innovation. Yet, in reality, copyrighted works face numerous close substitutes. In this paper, we formally model copyright using an approach better suited to the nature of copyrighted works – a model of differentiated-goods competition. We discuss the consequences of improperly viewing copyright as monopoly. While theoretically formal, the paper is intended to inform public policy with respect to copyright and is thus presented in a way accessible to the non-economist.