Parliamentary democracy is the most common way of organizing delegation and accountability in contemporary democracies. Yet knowledge of this type of regime has been incomplete and often unsystematic. This book aims to provide conceptual clarity on the topic. Taking principal-agent theory as its framework, the work illustrates how a variety of apparently unrelated representation issues can now be understood. This procedure allows scholarship to move well beyond what have previously been cloudy and confusing debates aimed at defining the virtues and perils of parliamentarism.