Insurance Markets: Cars with Black Boxes

We examine the effects of ex post revelation of information about the risk type or the risk-reducing behavior of insureds in automobile insurance markets both for perfect com-petition and for monopoly. Specifically, we assume that insurers can offer a contract with information revelation ex post, i.e., after an accident has occurred, in addition to the usual second-best contracts. Under moral hazard this always leads to a Pareto-improvement of social welfare. For adverse selection we find that this is also true except when bad risks under self-selecting contracts received an information rent, i.e., under monopoly or under competition with cross-subsidization from low to high risks. Regula-tion can be used to establish Pareto-improvement also in these cases. Privacy concerns do not alter our positive welfare results