의료보험(醫療保險)의 상반(相反)된 선택(選擇), 도덕적(道德的) 위해(危害) 및 본인부담제(本人負擔制)의 이논적고찰(理論的考察) = Adverse Selection, Moral Hazard and Social Insurance

다국어 초록 (Multilingual Abstract)

As George Akerlof pointed out in his brilliant study of the used car market, informational asymmetry can lead to certain types of market failure. In this paper, I examine two cases in which informational asymmetry could interfere with the operation of health insurance markets.
One is the case of adverse selection, in which the insurer cannot determine some character-istics of the insured that are relevant to the determination of the probability of the future state of nature. I show that ``extreme`` adverse selection could lead to the collapse of health insurance markets.
The other case is moral hazard which refers here to the tendency of insurance protection to alter an individual`s motive to prevent loss;in other words, the insured has the power and ince-ntive to change the present slate of nature. I also show that competitive equilibrium under moral hazard could lead individuals to overconsume insurance and under-consume loss prevention. I suggest that compulsory public insurance may produce an improvement over the market outcome. Coinsurance scheme may be one of optimal solutions in this kind of moral hazard situation. But I also show that the rising coinsurance rate could produce the undesirable outcome that it decreases ·the demand of poor class severer than that of rich class.