Decentralisation refers to the transfer of powers and responsibilities from the central government level to elected authorities at the subnational level (regional governments, municipalities, etc.) and that have some degree of autonomy. Decentralisation covers three distinct but interrelated dimensions: political, administrative and fiscal. There has been a path towards decentralisation in a majority of OECD countries over the past decades. In two thirds of OECD countries, decentralisation processes have resulted in an increase of economic importance of subnational government, measured both as a spending share of GDP and share of total public spending between 1995 and 2016.
Today, regions and cities represent account for 40.4% of public spending and 56.9% of public investment in the OECD. Regions and cities play an increasing role in key policy areas linked to megatrends, such as transport, energy, broadband, education, health, housing, water and sanitation. They are responsible, for example, for 64% of environment and climate-related public investment.
The forms and extent of decentralisation vary greatly from one country to another. The financing systems for subnational governments also vary significantly, cutting across federal versus unitary distinctions. On weighted average, taxes represented the number one source of revenues for subnational governments in the OECD (45%), followed by grants and subsidies (37%).
But, decentralisation is too often understood as a simple increase in the power of local governments. The reality is much more complex, as most responsibilities are shared across levels of government. Decentralisation is also about reconfiguring the relationships between the central government and subnational governments towards a greater cooperation and a strategic role for national/federal governments.
Decentralisation trends around the world have gone hand in hand with an upscale in subnational governance through municipal cooperation, metropolitan governance, and the strengthening of regions. Municipal fragmentation has driven policies encouraging or imposing amalgamations and municipal cooperation. However, it remains high in some countries. Municipalities having less than 5 000 inhabitants represent 44% of all municipalities in the OECD. In 10 countries, this ratio exceeds 80%. The number of metropolitan governance authorities created has increased, regardless of type, in particular since the 1990s. The rising role of administrative regions has also been striking: of the 81 countries, 52 experienced a net increase in the degree of regional authority since the 1970s (as measured by the Regional Authority Index).
In parallel to decentralisation, there has also been an increase in asymmetric decentralisation, i.e. the fact that governments at the same subnational government level have different political, administrative or fiscal powers. While asymmetric decentralisation appears more “natural” in federal countries, it is increasing in unitary countries.