Existence of Equilibria in Competitive Insurance Markets
Author: Peter S. Faynzilberg
Publisher:
Published: 2006
Total Pages:
ISBN-13:
DOWNLOAD EBOOKUnder the conditions conjectured by Rothschild and Stiglitz (1976)as leading to market failure, we demonstrate the existence of a uniqueequilibrium in a risk-sharing economy with adverse selection. This equilibrium may be separating or partially pooling: in an economy withthree types, for instance, the low- and the medium-risk buyer segmentsmay be offered the same insurance policy.In equilibrium, buyers' indirect utility decreases with their propensityfor accident. When low-risk buyers are prevalent, sellers subsidizetheir operations across segments: they derive a positive profit in thelow-risk segment and incur a loss of equal magnitude in the rest ofthe economy. This leaves high-risk buyers better off than under thefirst-best policy they purchase when sellers are perfectly informed.In contrast to the putative equilibrium of the Rothschild-Stiglitzmodel, the second-best equilibrium depends on the structure of thebuyer population and converges to the first-best of the correspondinghomogeneous population as low- risk buyers become increasingly prevalentin the economy.