Despite facing challenges at the domestic level along with a rapidly transforming global landscape, the U.S. economy is still the largest and most important in the world. The U.S. economy represents about 20% of total global output, and is still larger than that of China. Moreover, according to the IMF, the U.S. has the sixth highest per capita GDP (PPP). The U.S. economy features a highly-developed and technologically-advanced services sector, which accounts for about 80% of its output. The U.S. economy is dominated by services-oriented companies in areas such as technology, financial services, healthcare and retail. Large U.S. corporations also play a major role on the global stage, with more than a fifth of companies on the Fortune Global 500 coming from the United States.