This paper aspires to provide an overview of the issue of diversity of banking and financial systems and its development over time from a positive and a normative perspective. In other word: how different are banks within a given country and how much do banking systems and entire financial systems differ between countries and regions, and do in-country diversity and between-country diversity change over time, as one would be inclined to expect as a consequence of globalization and increasingly global standards of regulation?
As the first part of this paper shows, the general answer to these questions is that there is still today a surprisingly high level of diversity in finance. This raises the two questions addressed in the second part of the paper: How can the persistence of diversity be explained, and how can it be assessed? In contrast to prevailing views, the author argues that persistent diversity should be regarded as valuable in a context in which there is no clear answer to the question of which structures of banking and financial systems are optimal from an economic perspective.