中文摘要：

通过引入制度设计理论，分析联保小组成员合作行为形成和维持的基本条件，以最优化理论为工具分析影响小组联保制度的激励与约束因素。小组联保制度通过小组中心会议制度和成员资格、连带责任制、自愿参加原则和违约惩罚机制以及利用社会资源来满足博弈的均衡条件，在理论上联保小组成员之间经过博弈最终会形成合作均衡，但均衡工作努力水平和监督强度却决定于投资收益、利率、社会制裁、再次贷款的机会成本、连带责任、停止贷款威胁以及共谋行为等众多因素。

英文摘要：

This paper analyses the basic conditions of the formation and maintenance of cooperative behavior of the group members by introducing the system design theory, and analyses the incentive and constraint factors of the group lending system by the optimization theory, The group lending institution meet the equilibrium condition of game through the system of group center meeting and membership, the joint liability, the principle of voluntariness, the punishment mechanism and the use of social resources. In theory, a cooperative equilibrium will be eventually formed between the group members after the game, but the equilibrium effort level and the supervision strength are decided by many factors such as return, interest rates, social sanctions, opportunity cost of new loans, joint liabil- ity, stop lending threat and collusive behavior.