This barometer aims to show in a concise and simple way the main parameters of the horizontal and vertical organization of levels of local administration in countries of Greater Europe. It gives a state of play on levels and strata of local authorities in Europe as well as evolutions and reforms that have taken place as a consequence of the financial crisis since 2008. It gives landmarks and a clear idea of local reforms that have taken place in Europe in the past 10 years.

Simplification of the role and action of local authorities is at the heart of current debates on local reforms, and it is with this perspective in mind that the Barometer aims to give us the capacity to follow and analyse the evolution of territorial structures and therefore the institutional architecture of territories as reforms are undertaken. The current hypothesis is that modernity is about merging local authorities. However, this remains to be proved as it is difficult to demonstrate that economic efficiency results from the size of territorial structures. Doubts remain for if local authorities of too small a size are not ideal, too large ones are not ideal either.