The concept of accountability is not by itself problematic, or at least it should not be. We say that one person, A, is accountable to another, B, if two conditions are met. First, there is an understanding that A is obliged to act in some way on behalf of B. Second, B is empowered by some formal institutional or perhaps informal rules to sanction or reward A for her activities or performance in this capacity. In this sense, employees are accountable to their employers, CEOs to their boards and their boards to stockholders, department chairs to the departments they represent, and elected politicians to their electorates. In the jargon of economic theory, relations involving accountability are agency relationships in which one party is understood to be an “agent” who makes some choices on behalf of a “principal” who has powers to sanction or reward the agent.

Most interesting questions about accountability in political and economic contexts concern not its definition but rather the understanding of what activities or performance the agent is accountable for, the nature of the principal's sanctioning or rewarding instruments, and the problem of to what extent a given system of incentives will lead the agent to act on behalf of the principal, that is, to do what the principal would want. In addition, in the case of electoral accountability, additional problems arise from the presence of multiple principals (voters, but perhaps also courts and other elected officials in some cases) rather than a single principal or a collective body that can act as a single principal.