premise: The world's second largest economy by GDP is China.
hypothesis: China . , it is the world 's second-largest economy by nominal GDP and largest by purchasing power parity ( PPP ) . China 's socialist market economy is the world 's second largest economy by nominal GDP , and the world 's largest economy by purchasing power parity according to the IMF , although China 's National Bureau of Statistic denies this claim . The United States is the world 's largest national economy in nominal terms and second largest according to purchasing power parity ( PPP ) , representing 22 % of nominal global GDP and 17 % of gross world product ( GWP ) .