健康保險道德風險的理解與誤解

Understanding and misunderstanding moral hazard in health insurance

道德風險概念對各國健康保險政策影響極為深遠，而其長久以來爭議的根源有二，第一來自道德風險的定義轉變，第二則來自道德風險的理論競爭。對於健康保險「道德風險」的理論演變而言，台灣本土文獻缺乏對這個理論的詮釋與追蹤，因此對這個觀念的「誤解」也就特別普遍。本文的目的在於釐清這個理論爭議的歷史軌跡，同時提出新的觀點來建議健康保險道德風險理論及政策可以發展的方向。本文先介紹道德風險在代理關係上最原始的定義，再介紹其後衍生在消費者誘因上的定義。透過第二個定義中的價格效果，以及其背後所牽涉到的健康保險需求理論，來論述道德風險理論在政策應用上的誤解與誤用，然後介紹道德風險的第三個定義中的所得效果，來修正價格效果的政策誤解。透過這種概念的釐清，本文同時提出兩種新的觀點，來建議健康保險「道德風險」理論可以發展的方向。最後本文針對健康保險「道德風險」理論的變遷對台灣社會的政策意義進行論述，並以此作為本文的結論。

The concept of moral hazard has profound impacts on many countries' health insurance policies. Its theoretical framework, however, has been contentious among academics, especially health economists. This academic debate originated from two major sources: the transformation of the definition of, and the competition among different theoretical foundations for moral hazard. The inquiry about the definition and transformation of moral hazard has largely been absent from Taiwan's academic literature. Consequently, misunderstandings about the concept of moral hazard in health insurance abound in Taiwan's academic and policy worlds. The purpose of this article is to investigate the historical development of and transformation in defining moral hazard, and to introduce a new conceptual framework of moral hazard and its policy implications. We begin by introducing the original definition of moral hazard in the context of agency relationships, followed by discussing moral hazard in the framework of consumer incentives. Through the discussion of the price effect of moral hazard and its related theory on the demand for health insurance, we discuss how theory of moral hazard has been frequently misunderstood and misused in health policies. This is followed by discussing the income effect of moral hazard and how it can correct the misunderstandings of price effect of moral hazard in health policies. Further, we also introduce new concepts of moral hazard and propose a future direction of research on health insurance-related moral hazard. Finally, we discuss the significance and implications of the transformational concept of moral hazard to Taiwan's social policies.