the paper concludes with a brief note on the way forward for the oecd as a whole the tax to gdp ratio rose from of gdp in to in the tax mix also varies reflecting a host of determinants including among others the structure and openness of the economy intergovernmental arrangements eg unitary versus federal structure box the institutional capacities of the national and subnational government administrations and collective attitudes toward income redistribution and the use of progressive taxation subcentral entities generate their own revenues to varying degrees