Inter-municipalities: scapegoats for the increase in local taxes in France?

Summary Some, such as deputy Hervé Mariton in his report on the evolution of local taxation published in 2005, maintain that "inter-municipal cooperation would be a significant factor in the increase of local tax rates in France". The taxation of the communal block increased by 12.09% over the period 1997-2009. Over the same period, the number of Établissements Publics de Coopération Intercommunale (EPCI) increased from 1,446 to 2,601. Is there indeed a causal link between the creation of EPCIs and the increase in local taxation? If so, how does the size of the communes and the EPCI's tax system modify the impact of intermunicipal cooperation on local taxation? What are the different economic mechanisms at work?