Accountability means being held to account, scrutinised, and being required to give an account or explanation.
In politics, and particularly in representative democracies, accountability is an important factor in securing good governance. Accountability differs from transparency in that it only enables negative feedback after a decision or action, while transparency also enables negative feedback before or during a decision or action. Accountability constrains the extent to which elected representatives and other office-holders can willfully deviate from their theoretical responsibilities, thus reducing corruption.
The goal of accountability is at times in tension with the goal of leadership. A constituency may have short-term desires which are at odds with long-term interests.
See also: campaign finance reform.