Traditionally, political power in Samoa was held by matai (chiefs), whose positions were generally inherited, although individuals with charisma and power can earn positions. The matai system survives to the present day, but was changed during the colonial and post-colonial periods. Political turbulence characterized the 19th century in Samoa, during which matai-lead governments formed and reformed, often with support from traders, missionaries, and other foreigners. In 1899 the colonial powers of Germany, Great Britain, and the United States resolved this impasse for their own purposes by signing a treaty granting Germany control of Western Samoa and the United States control of Eastern (American) Samoa. Western Samoa, however, was occupied by New Zealand during World War I and was a colony of that country until it gained independence in 1962. In the 1920s the Mau movement, advocating non-payment of tax and whose ultimate goal was independence, was formed. The movement was suppressed by New Zealander troops in the late 1920s but it remains a symbol of nationalism to the present day.
Samoa has a parliamentary system with the Paramount Chief of Samoa as the ceremonial head of state. Until 1991, members of Parliament were elected by the matai, but in that year universal suffrage for all citizens 21 years and over was introduced. Tradition is still maintained, however, since only matai can be elected to 1 of the 49 parliamentary seats. There are 2 main parties, the Human Rights Protection Party and the Samoa National Development Party, but these parties tend to revolve around personalities more than political positions that allow them to be labeled left, center, or right.
Until recently the main domestic sources of government revenue were trade tariffs and, to a lesser extent, income taxes . In 1994, a value added goods and services tax (VAGST) was introduced despite popular opposition. The VAGST of 10 percent is imposed on most items of consumption including imports, with exceptions including unprocessed local primary production, financial services, and hospital and educational services. Since this tax's creation, most individuals do not have to pay income tax and trade tariffs have been reduced.