The economy of Norway is a developed mixed economy with state-ownership in strategic areas. Although sensitive to global business cycles, the economy of Norway has shown robust growth since the start of the industrial era. Shipping has long been a support of Norway's export sector, but much of Norway's economic growth has been fueled by an abundance of natural resources, including petroleum exploration and production, hydroelectric power, and fisheries. Agriculture and traditional heavy manufacturing have suffered relative decline compared to services and oil-related industries, and the public sector is among the largest in the world as a percentage of the overall gross domestic product. The country has a very high standard of living compared with other European countries, and a strongly i