The Logic of Moral Hazard: A Game Theoretic Illustration
用n人博弈模型说明，在健康保险中个人倾向于过度使用医疗资源，即使考虑对保费的影响也不愿节约，并提出基于个人评级的解决方案。
When individuals behave differently in the presence of insurance than in the absence of insurance, the problem faced by the insurer is known as moral hazard. There are several ways moral hazard can manifest itself in individual behavior. Insured individuals may exercise less caution (e.g., smoking). When health care resources are required, insured individuals may seek professional intervention at a lower level of illness severity, demand a higher quality of care, or not shop as carefully for least cost providers as uninsured individuals. Dionne (1981) provides a review of the different types of moral hazard and the effect of moral hazard on search activity. An underlying theory of health economics holds that an individual tends to view health insurance premiums as exogenously determined sunk costs unaffected by consumption of additional health care resources. Individuals view premiums as sunk costs because they are paid at regular intervals during the year, not at the time health care services are purchased. Individuals view premiums as exogenously determined because premium quotations are based on group-experience rates, not the specific health expenditure record of the policyholder. Individuals of an experience rated group participate in an n-person game. The purpose of this paper is to provide a simple illustration of the problem of moral hazard within the context of n-person games. The rational choice for any individual is overutilization of health care resources. The illustration also shows that even if individuals take into account the effect of their own consumption on premiums they will still choose not to conserve. A solution based on merit rating is proposed.