The United States is the world’s largest national economy in nominal terms and second largest according to purchasing power parity (PPP), representing 22% of nominal global GDP and 17% of gross world product (GWP). The United States’ GDP was estimated to be $17.914 trillion as of Q2 2015. The U.S. dollar is the currency most used in international transactions and is the world’s foremost reserve currency, backed by its science and technology, its military, the full faith of the US government to reimburse its debts, its central role in a range of international institutions since World War II and the petrodollar system. Several countries use it as their official currency, and in many others it is the de facto currency. The United States has a mixed economy and has maintained a stable overall GDP growth rate, a moderate unemployment rate, and high levels of research and capital investment. Its seven largest trading partners are Canada, China, Mexico, Japan, Germany, South Korea, and the United Kingdom.
The US has abundant natural resources, a well-developed infrastructure, and high productivity. It has the world’s ninth-highest per capita GDP (nominal) and tenth-highest per capita GDP (PPP) as of 2013. Americans have the highest average household and employee income among OECD nations, and in 2010 had the fourth highest median household income, down from second highest in 2007. It has been the world’s largest national economy (not including colonial empires) since at least the 1890s.
The U.S. is the world’s third largest producer of oil and natural gas. It is one of the largest trading nations in the world as well as the world’s second largest manufacturer, representing a fifth of the global manufacturing output. The US not only has the largest internal market for goods, but also dominates the trade in services. US total trade amounted to $4.93T in 2012. Of the world’s 500 largest companies, 128 are headquartered in the US.
The United States has one of the world’s largest and most influential financial markets. The New York Stock Exchange is by far the world’s largest stock exchange by market capitalization. Foreign investments made in the US total almost $2.4 trillion, while American investments in foreign countries total over $3.3 trillion. The economy of the U.S. leads in international ranking on venture capital and Global Research and Development funding. Consumer spending comprises 71% of the US economy in 2013. The United States has the largest consumer market in the world, with a household final consumption expenditure five times larger than Japan’s. The labor market has attracted immigrants from all over the world and its net migration rate is among the highest in the world. The U.S. is one of the top-performing economies in studies such as the Ease of Doing Business Index, the Global Competitiveness Report, and others.
The US economy went through an economic downturn following the financial crisis of 2007–08, with output as late as 2013 still below potential according to the Congressional Budget Office. The economy, however, began to recover in the second half of 2009, and as of November 2015, unemployment had declined from a high of 10% to 5%.
In December 2014, public debt was slightly more than 100% of GDP. Domestic financial assets totaled $131 trillion and domestic financial liabilities totaled $106 trillion.