Ambiguity is intrinsic to life. Yet, mainstream accountability theory reduces its area of application by not taking ambiguity seriously. The literature treats too many aspects as exogenous to politics and is unlikely to capture accountability dynamics in contemporary representative democracies in transformation, including the European Union. Theorizing accountability requires going beyond predetermined principals and agents, detecting deviance from authoritative orders and rules, and disciplining unruly agents. An institutional perspective is offered, relaxing assumptions regarding what accountability means and implies; what is (...) involved in demanding, rendering, assessing and responding to accounts; what factors foster effective accountability; and how accountability regimes emerge and change. The fluidity and unresolved conflicts of political life make it difficult to correctly assign causal responsibility and to learn from experience. Accountability processes, nevertheless, provide occasions for searching for and testing collective purpose, intelligence, meaning and political equality, as part of institutionalization and de-institutionalization processes. (shrink)