 In this regard, the new rules for fiscal decentralisation in force since 2011 already make Spain one of the most decentralised countries in the world also in budgetary and fiscal matters, with the base for income tax split at 50/50 between the Spanish government and the regions (something unheard of in much bigger federal states such as Germany or the United States, which retain the income tax as an exclusively or primarily federal one).Besides, each region can also decide to set its own income tax bands and its own additional rates, higher or lower than the federal rates, with the corresponding income accruing to the region which no longer has to share it with other regions.This current level of fiscal decentralisation has been regarded by economists such as Thomas Piketty as troublesome since, in his view, "challenges the very idea of solidarity within the country and comes down to playing the regions against each other, which is particularly problematic when the issue is one of income tax as this is supposed to enable the reduction of inequalities between the richest and the poorest, over and above regional or professional identities".