對調與邊界兩概念是認識寇斯貢獻的最重要基礎。一旦偏離這兩個堅強的基礎，一位學者往往就會扭曲或誤解寇斯所發揚的交易成本概念，以及他在廠商與財產權本質問題上的洞見。本文藉由一對父女書信往返討論的對話情境，深入淺出地回顧寇斯主要貢獻。本文也針對寇斯遭受到學術界的曲解與嚴厲批評一一提出反駁。其中，在純粹的理論方面，最重要的莫過於交易成本具主觀本質以及交易成本為零下畢竟沒有財富效果。除此外，文中也說明如何正確地以寇斯的貢獻來了解台灣經濟政策上的一些謬誤。

Reciprocity and boundary are the most important foundation to understanding Coase’s contribution. Deviating from the two solid foundations will result in a misunderstanding or distortion of Coase’s idea of transaction cost and his insights into the nature of the firm and property rights. This article succinctly reviews Coase’s major contribution in a dialogue context of discussing mails between a father and a daughter. In addition, this article refutes harsh and distorting criticisms against Coase. In the aspect of pure theory, the most important points are the subjective nature of transaction cost and that there can be no wealth effect under the assumption of zero transaction cost. This article also demonstrates how to correctly apply Coase’s insights to detect problems of some of Taiwan’s recent economic policies.