An Evolutionary Analysis of Insurance Markets
Since the seminal work by Rothschild and Stiglitz on competitive insurance markets under adverse selection the problem of non-existence of equilibrium has puzzled many economists. In this paper we approach this problem from an evo- lutionary point of view. In a dynamic model insurance companies remove loss- making contracts from the market and copy pro t-making ones. Occasionally, they also experiment, adding new contracts or removing current ones arbitrarily. We show that the Rothschild-Stiglitz outcome arises in the long run if it consti- tutes an equilibrium in the static framework, but also if it is not an equilibrium, provided that rms only experiment with contracts in the vicinity of their current portfolio.