This chapter provides an extended discussion on the choice of design and structure of analysis, including the handling of alternative explanatory themes such as modernization and economic growth but also the role of phenomena closely linked to corruption such as state fragility and government effectiveness. The measurement of corruption is given much emphasis since it is key to the book's argument. Corruption is commonly defined as the abuse of public office for private gain (the World Bank) or the abuse of entrusted power for private gain (Transparency International) but the chapter highlights that there is no universally agreed way of measuring this phenomenon. Central to this book is the type of corruption that involves different levels of government. The chapter discusses relevant indicators where the common denominator is that they focus on public officials and the misuse of public resources whether in the form of “grand corruption,” involving large sums and taking place at elite levels of society, or “petty corruption,” involving smaller sums and taking place in interactions between citizens and civil servants.