The Republic of Venezuela in northern South America is approximately 912,000 square kilometers and is bounded by Guyana on the east, Brazil on the south, Colombia on the west, and the Caribbean Sea on the north. One of the world's leading oil producers, Venezuela has the highest per capita income in Latin America. Economic rights include the right to own property, an economic system based on social justice, and prohibition of monopolies. Venezuela is a federal state, in which power is divided among the nation, the states, and the municipalities. The role of the judiciary is somewhat diminished, however, by the lack of life tenure and the reliance on both the executive and legislative branches for their salaries. A general revision of the constitution requires initiation of a proposal by one-third of the members of the national legislature or by an absolute majority of the state legislatures.