The United States has a capitalist mixed economy. The private sector constitutes the bulk of the economy, with government activity accounting for 12.4 percent of the GDP. Most businesses economy in the U.S. are sole proprietorships with no payroll. Both the regulatory burden on its companies and its social safety net are smaller than in most developed nations. According to the International Monetary Fund, the United States GDP of more than $13 trillion constitutes 20 percent of the gross world product. The country ranks eighth in the world in nominal GDP per capita and fourth in GDP per capita at purchasing power parity.

The economy is fueled by abundant natural resources, a well-developed infrastructure, and high productivity. Americans tend to work considerably more hours annually, take less vacation, and produce more per hour than workers in other developed nations. In 2005, 155 million persons were employed with earnings, of whom 80 percent worked in full-time jobs. The majority, 79 percent, are employed in the service sector. The United States is the largest importer of goods
and second largest exporter. Canada, China, Mexico, Japan, and Germany are its top five trading partners.