This paper is based on the structural model proposed by Cohen and Einav [2007]to estimate the joint distribution of risk and risk aversion in the automobile insurancemarket. However, while they estimated the model for a single insurer in the Israelimarket, we estimated the model by considering the top ve insurers in the Brazilianmarket at the same time. This difference allowed us to capture the eect of competitionon the joint distribution of risk and risk aversion. A counterfactual exercise allowedus to verify that the insurer with the largest market share can implement the optimalcontract, while the others do not.