The economy of the Allied States is the largest economy in the world. Its nominal GDP was estimated to be over $6.1 trillion in 2010. The economy maintains a very high level of output. In 2011, it was estimated to have a per capita GDP (PPP) of $59,302, the 4th highest in the world, thus making A.S. one of the world's wealthiest nations. The A.S. is one of the largest trading nations in the world. Its three largest trading partners as of 2012 are the Northern Coalition of America and Canada, the United Commonwealths of America, Mexico and the Russian Federation. The economy of the Allied States is a mixed economy and has maintained a stable overall GDP growth rate, a moderate to high unemployment rate, and high levels of research and capital investment.