One of the most prevalent themes in the accountability literature is claims about the ‘amount’ of accountability that applies in a given situation. There are claims of accountability ‘deficits’ (ie too little accountability) on the one hand, and claims of accountability ‘overload’ (ie too much accountability) on the other. This chapter draws out these claims and argues that, while these claims presuppose that accountability is a measurable concept, the literature often glosses over the underlying question of what is being measured, or how the measurement is to be conducted. This missing dimension of the literature is the core problem tackled in this book, which unpacks two of the hidden assumptions that underlie these claims. The first of these assumptions is that it is possible to identify some form of accountability benchmark, being a normative judgement as to the ‘ideal amount’ of accountability against which an arrangement can be measured and found wanting. The second is that it is possible to assess the universe of applicable accountability mechanisms against that benchmark, and to form a judgement as to whether the system underperforms (deficit) or overperforms (overload).