The multiple principal problem, also known as the common agency problem, the multiple accountabilities problem, or the problem of serving two masters, is an extension of the principal-agent problem that explains problems that can occur when one person or entity acts on behalf of multiple other persons or entities.[1] Specifically, the multiple principal problem states that when one person or entity (the "agent") is able to make decisions and / or take actions on behalf of, or that impact, multiple other entities: the "principals", the existence of asymmetric information and self-interest and moral hazard among the parties can cause the agent's behavior to differ substantially from what is in the joint principals' interest, bringing large inefficiencies. The multiple principal problem has been used to explain inefficiency in many types of cooperation, particularly in the public sector, including in parliaments, ministries, agencies, inter-municipal cooperation, and public-private partnerships, although the multiple principal problem also occurs in firms with multiple shareholders.[2][3]