For some comprehensive measures such as the framework to address risks posed by systemically important financial institutions, hard work remains to be done, in particular through the Financial Stability Board, to clarify the concept of systemically important institutions, to investigate the properties of the pertinent tools – additional capital requirements, contingent capital, bail-in instruments, etc.
That explains why trends are so difficult to substantiate, and conjectures not easily proved or rejected: the two effects underlined by Krugman on the one hand and by Frankel and Rose on the other hand, are probably operating simultaneously in the euro area, together with the universal phenomenon of agglomeration or clusterisation.