The Czech Republic has a developed, high-income export-oriented social market economy based in services, manufacturing and innovation, that maintains a welfare state and the European social model. The Czech Republic participates in the European Single Market as a member of the European Union and is therefore a part of the economy of the European Union, but uses its own currency, the Czech koruna, instead of the euro. It has a per capita GDP rate that is 91% of the EU average and is a member of the OECD. Monetary policy is conducted by the Czech National Bank, whose independence is guaranteed by the Constitution. The Czech Republic ranks 12th in the UN inequality-adjusted human development and 24th in World Bank Human Capital Index. It was described by ''The Guardian'' as "one of Europe's most flourishing economies".