From the introduction of the editors:

Diversity is often claimed to be a potential for the development of Europe. But this has many meanings and can refer to differences in levels of development or in cultural and institutional contexts of member countries. Pascal Petit’s contribution argues that the EU is not in a position to support a rapid catching up of the new members and has difficulties in monitoring the institutional changes that would take advantage of the institutional diversity of the other members. He stresses that the monitoring of institutional diversity as addressed by the method of open coordination is ill suited, unless it is extensively reformed to take into account the systemic aspect of national institutions and the contingencies and path dependant nature of institutional changes