憲法保障人民之工作權，然而，國家為保障民眾權益，也會透過強制力以各種不同的方式介入勞務市場。「職業證照管制」乃是其中相當重要的一項。因為透過證照管制，將會對於執業者的市場帶來正反兩面不同程度的影響。傳統奠基於福利經濟學的市場失靈理論，對於證照管制出現的解釋似乎不盡完整。因證照管制往往牽涉到政治過程之運作，而涉及諸多參與者的利益，因此，本文以利益團體的概念 (concept of interest group) 為基礎，重新架構一個職業證照管制的理論模式。在各個利益團體競逐「管制」這項商品的政治過程中，相關團體皆依其成本效益考量決定其最適之行動模式，透過「管制」需求面與供給面的互動，從而決定出最後均衡的管制產出。此外，與先前文獻不同的是，在各團體的行動中，本文加入「交易成本」觀點 (concept of transaction cost) ，更將公眾利益的考量以「意識型態」的方式加入管制供給者的行動模式之中，以建構出更具有解釋力之證照管制理論模式。本文更將此一模式應用分析於「土地登記專業代理人」證照管制案例中，且啟示頗具效果，值得重視。

The constitution protects the right to work. However, the government may intervene professional market in many ways through coercive power. Occupational licensure is one of the most important one among them, because it brings about enormous influences both positively and negatively on the market. The market failure theory based on traditional welfare economics seems to be incomplete in explaining the occurrence of occupational licensure. Thus, this article reconstructs a theoretical model for occupational licensure based on the concept of interest group theory. In political process where interest groups seek the product of regulation, each group takes its optimal action according to cost-benefit considerations. The interactions between demand side and supply side of regulation determine the equilibrium condition. Differing from earlier studies, this article applies the concept of transaction cost and takes into account the public interest of the supply side under regulation, constructing a more powerful theoretical model. Moreover, this article applies this model to the case of conveyancer and shows how it works well and gives the important implications