High Quality Content by WIKIPEDIA articles! The economy of Iran is the eighteenth largest in the world by purchasing power parity (PPP) and according to Iranian officials` claims is going to become the 12th largest by 2015. The economy of Iran is a mixed and transition economy with a large public sector and some 50% of the economy centrally planned. It is also a diversifed economy with over 40 industries directly involved in the Tehran Stock Exchange. Yet, most of the country`s exports are oil and gas, accounting for a majority of government revenue in 2010.