Dominica is an island country located in the Caribbean Sea and North Atlantic Ocean, about halfway between Puerto Rico and Trinidad and Tobago. Dominica is tropical with rugged mountains of volcanic origin. The government system is a parliamentary democracy; the chief of state is the president, and the head of government is the prime minister. Dominica has a mixed economic system which includes a variety of private freedom, combined with centralized economic planning and government regulation. Dominica is a member of the Caribbean Community (CARICOM) and the Organization of Eastern Caribbean States (OECS).