 Nonetheless Spain is now a decentralized country with a structure unlike any other, similar but not equal to a federation, even though in many respects the country can be compared to countries which are undeniably federal.The unique resulting system is referred to as "Autonomous state", or more precisely "State of Autonomies".With the implementation of the Autonomous Communities, Spain went from being one of the most centralized countries in the OECD to being one of the most decentralized; in particular, it has been the country where the incomes and outcomes of the decentralized bodies (the Autonomous Communities) has grown the most, leading this rank in Europe by 2015 and being fifth among OECD countries in tax devolution (after Canada, Switzerland, the United States and Austria).