This chapter presents the methodology used in forming a comprehensive institutional diagnostic of the four case study countries included in the IDP project. An institutional diagnostic of development is defined as an exploration of how the institutions of a country affect the functioning of its economy, its dynamics, and the policymaking process, the ultimate goal being to detect the most serious flaws that hinder development. The methodology includes three steps. A first step reviews the economic, social, and political development of the country, examining institutional quality indicators, and soliciting from various types of decision makers their views on potential institutional obstacles to development. The second step consists of an in-depth analysis of selected critical economic areas, where the relationship between the institutional context of a country and its development is the most apparent. The third step synthesises what has been learned into a list of basic institutional problems, their economic consequences, and, most importantly, their causes, proximate or more distant, as well as the potential for reforms in view of the political economy context.