服务供应商角色外行为的契约激励机制研究

Research on Contract Incentive Mechanism for Extra-Role Behavior of Service Provider

针对如何激励服务供应商的角色外行为,构建面向角色内行为的正式契约、面向角色内和角色外行为的关系契约以及社会效益最大化的最优契约三种契约下的委托代理模型,求解各契约下的最优契约条款和发包方长期最优收益,分析建立关系契约的条件和最优角色内和角色外行为激励系数,对比分析三种契约下发包方长期最优收益。越重视长远利益的发包方所获长期最优收益越大,且越愿意为服务供应商角色外行为提供更多激励。当贴现率大于一定值时,发包方和服务供应商才会建立关系契约。发包方会提高对服务供应商角色外行为的激励系数,以吸引服务供应商与其签订关系契约。服务供应商角色外行为会为发包方带来额外收益,且该额外收益与贴现率和角色外行为效用权重正相关。

Focusing on how to incent service provider′s extra-role behavior,three principle agent models were constructed to study the incentive mechanism of these three types of contracts:formal contract for in-role behavior,relational contract for in-role and extra-role behavior and optimal contract maximizing the social benefit.Optimal contract terms and client′s long-term optimal revenue were obtained by solving the above models.The prerequisite to concluding relational contract and the incentive factor for extra-role behavior under relational contract were analyzed.The comparison between the long-term optimal revenues of the three types of contracts were conducted.The client who attaches more importance to the long-term benefits gained more revenue and provided more incentive for the service provider′s extra-role behavior.The relational contract will be established only when the discount rate is greater than a certain value.The client will set a greater incentive factor to attract the service provider to accept the relational contract.Service provider′s extra-role behavior brings extra revenue to the client and the extra revenue is positively correlated with discount rate and extra-role behavior′s utility weight.