中文摘要：

已有关于社会资本的理论和文献多是分析社会资本的不同形式及其对经济发展的影响，而没有分析社会资本得以存在的个体理性基础。引入行为经济学中的“社会偏好”这一概念，可以对主流经济学中个体理性的内涵进行扩展，并通过对个体层面社会资本的分析，揭示现实经济生活中存在的不同于市场交易的资源流动方式——“信任性交易”。这一方式的运行以交易双方建立的信任关系为基础，由于个体社会偏好具有异质性，随着网络中频繁的交易互动和信息的广泛传播，网络中的信任关系呈非均匀分布，一些个体会逐渐成为网络中的共同权威。

英文摘要：

Until now, most literatures on social capital have focused on the diverse influences on development of economy which social capital has. But few of them analyzed how the conception can be awilable in neoclassical economics based on the individualistic rational choice.This paper analyzes the social capital of individual level by taking the conception ＂social preference＂ from behavior economics into the standard theory. And the authors find that there is a kind of transaction,＂transaction based on trust＂, which works well based on the trust but net contracts. Since people are diversified in ＂social preference＂, the strength of trust between people in the social networks is not uniformly distributed, and some of them will become the respected authority of the social networks as a result of frequent interactions and diffusion of information.