The Tongans primarily live on a group of islands (islands of Tonga, also known as the Friendly Islands) in the South Pacific Ocean. Prior to the 1980s Tongans were primarily self-sufficient horticulturalists and fishers. A western Pacific chiefdom that was never colonized, Tonga established its own constitutional monarchy in 1875 and in 1970. Tonga became an independent country. Tonga has been the focus of anthropological interest in ranked societies and more recently a "remittance" economy based on the transnational network of emigrants. One-quarter to one-third the population lives abroad.