Government accountability is generally accepted to be an essential feature of modern democratic society; while others might turn a blind eye to corruption and wrongdoing, those who value accountability would instead shine a bright light on it. In this context, it is common to hear claims of accountability 'deficit' (a particular mechanism or area is lacking in accountability) and 'overload' (a particular mechanism or area over-delivers on accountability). Despite the frequency of references to these concepts, their precise content remains undeveloped. This book offers an explanation, as well as a framework for future exploration, of these concepts. It highlights the difficulty of defining a benchmark that might be used to measure the amount of accountability in a particular situation, and also the challenge of mapping out accountability mechanisms as a system. While difficult, if accountability is indeed a foundational concept underpinning our system of government, there is merit in meeting these challenges head-on.