This book examines the efficient implementation of incentives for members of a credit union in comparison to alternative financial service providers and their organizational forms. In addition to optimization opportunities within the legal form of credit unions, alternative institutional frameworks for the operations of credit unions, such as public limited companies, are also analyzed. The information asymmetries caused by the continuous growth in membership and the differing incentives of members and the credit union are illustrated within the framework of general agency theory. By applying the results of agency theory, the development of credit unions is presented in comparison to alternative contract designs, and the coexistence of multiple participation options is analyzed.