Israel is a representative democracy with a parliamentary system, proportional representation and universal suffrage.[24][25] The Prime Minister serves as head of government and the Knesset serves as Israel's unicameral legislative body. Israel is a developed country and an OECD member, with the 43rd-largest economy in the world by nominal gross domestic product as of 2012. Israel has the highest standard of living in the Middle East and the third highest in Asia, and among the highest life expectancies in the world.