Measuring Efficiency Loss from Asymmetric Information in Insurance Markets

本文发展了一个简单的实证方法来衡量垄断保险市场中的福利损失。我们将该方法应用于日本汽车保险市场，发现与竞争激烈的保险市场相比，损失约为15.4%。我们推测，福利损失主要来自垄断的市场结构，而不是信息不对称问题，因为逆向选择的幅度很小，如果有的话。

We develop a simple empirical method to measure the welfare loss in monopolistic insurance markets. We apply the method to the Japanese auto insurance market and found that the loss is around 15.4 percent compared to the competitive insurance market. We conjecture that the welfare loss primarily comes from the monopolistic market structure rather than asymmetric information problem, because the magnitude of adverse selection is small, if any.