United Kingdom has the ninth-largest economy by an economic theory.
The United Kingdom is a developed country and has the world 's fifth-largest economy by nominal GDP and ninth-largest economy by purchasing power parity .	developed country	developed country	fifth-largest economy	List of countries by GDP (nominal)	GDP	Gross domestic product	ninth-largest economy	List of countries by GDP (PPP)	purchasing power parity	purchasing power parity	power	Power (international relations)
Purchasing power parity -LRB- PPP -RRB- is an economic theory that states that the exchange rate between two currencies equal the ratio of the currencies ' respective purchasing power .	economic theory	economic theory	exchange rate	exchange rate	purchasing power	purchasing power
