The Netherlands has a prosperous and open economy, which depends heavily on foreign trade. The economy is noted for stable industrial relations, moderate unemployment and inflation, a sizable current account surplus, and an important role as a European transportation hub. Industrial activity is predominantly in food processing, chemicals, petroleum refining, and electrical machinery. A highly mechanized agricultural sector employs no more than 3% of the labor force but provides large surpluses for the food-processing industry and for exports. The country has been one of the leading European nations for attracting foreign direct investment and is one of the four largest investors in the US.