In Which Countries Are Regional Governments Most Autonomous

The Regional Authority Index (RAI) measures the authority in self rule and shared rule exercised by regional governments with 96 countries on an annual basis over the period 1950-2018.

The dataset encompasses subnational government levels with an average population of 150,000 or more. Where appropriate, we code more than one regional tier, and code separately regions with a special autonomous statute or asymmetrical arrangements. Regional authority is measured along ten dimensions, five tap self-rule --institutional depth, policy scope, fiscal autonomy, borrowing autonomy, and representation-- and five capture shared rule --law making, executive control, fiscal control, borrowing control, and constitutional reform. The latest version includes metropolitan and indigenous regions alongside conventional regions.

Via Politics Stack Exchange. More data here. 

I've seen other indexes that look at only a single measure, either revenue collected or proportion of overall government spending.

Germany, at the top, affords its states lots of regional autonomy. I presume that the countries with a zero rating, most of which are small, simply don't have any regional governments to be autonomous that meet the study's criteria.

The cutoff between countries normally considered to have federal systems and those that are normally considered to be unitary is about 20. But, as an index approach rather than a categorical one reveals, the devil is in the details and federalism can be considered more of a continuum of regional autonomy (that can shift over time), rather than an either/or matter.

I am surprised at the relatively low levels of autonomy of Swiss cantons which are sometimes considered connected in a confederation rather than a true federal government, and were a model for Bosnia which is near the top of the list. I'm likewise surprised at how high up the list Germany ranks. Italy is also surprisingly high on the list for a country not always considered to have a federal as opposed to a unitary structure.

I'd be curious to see how the European Union viewed as a federal nation would rank although I imagine that it presents some conceptual issues as parallel institutions like the Council of Europe and NATO overlap heavily with it and it has different levels of "commitment" to its overall institutional structure.

The low ranking of the U.K. makes lots of sense to some extent, especially for regional governments within England, but what about the autonomy afforded to Scotland, Wales, and Northern Ireland, let alone its dependencies, which is quite significant?

The list for 2018 is as follows: