Structural and functional analysis of Buchanan’s constitutional contract

Buchanan attempted to seek new theoretical construction through the contract method by introducing elements such as ‘individual’, ‘veil of uncertainty’, ‘public choice’, ‘decision costs’, and ‘unanimous agreement principle’. He not only transformed the contract theory model but also interpreted the ideas of consensus politics in an acceptable manner. Specifically, ‘individuals’ are entities of choice and behavior, and the process of choice allows individuals to express different goals and interests. The ‘veil of uncertainty’ prompts individuals to think about issues from a fair point of view when interests cannot be identified and future prospects are unpredictable and to make choices that are beneficial for both themselves and the group. ‘Public choice’ can solve the problem of justice diversity because it does not exclude different or conflicting motivations and goals. ‘Decision costs’ and ‘external costs’ both limit the way collective decisions are made and help identify the normal consequences of constitutional choices. The ‘unanimous agreement principle’ gives everyone equal status, allowing each person the right to pursue their own goals and values and preventing others from abusing their power. The use of the aforementioned theoretical elements not only helps people discuss constitutional choices at a general level but also helps to present the true face of the collective decision-making process, thereby establishing an empirical theory about the actual logic of individual actions in the political system.