The water crisis in south-eastern Brazil (Section 5.2) and the energy shortages resulting from it are further constraining the picking up of the economy. In 2013, tax revenue and government expenditure stood at levels slightly below the respective OECD averages (see Basic Statistics). Environmental taxes make up a minor share of total tax revenue, while fiscal revenue from hydrocarbons and mining was 2.4% of GDP in 2013 (OECD, 2015c) (Chapter 3).