In addition to importing and exporting goods and services, a country can take part in global integration in another way. This mainly concerns the exchange of labour and capital as production factors. In terms of capital flows, the size and direction of foreign direct investment flows are a much-debated phenomenon. According to the internationally-used definition of the OECD, "foreign direct investment" (FDI) includes green-field investments abroad, as well as the acquisition of at least 10% of the shares of a foreign company. Other forms of international capital investments (ownership shares of less than 10%, or the exchange of debt instruments) are classified as "foreign portfolio investments" (FPI) in balance of payments statistics.