Economy of the United States

United States has a capitalist mixed economy, which is fueled by abundant natural resources, a well-developed infrastructure, and high productivity. According to the International Monetary Fund, the U.S. GDP of $15 trillion constitutes 23% of the gross world product at market exchange rates and over 20% of the gross world product at purchasing power parity (PPP). Though larger than any other nation's, its national GDP is about 5% smaller than the GDP of the European Union at PPP in 2008. The country ranks ninth in the world in nominal GDP per capita and sixth in GDP per capita at PPP. The U.S. dollar is the world's primary reserve currency.
The United States is the largest importer of goods and third largest exporter, though exports per capita are relatively low. In 2008, the total U.S. trade deficit was $696 billion. Canada, China, Mexico, Japan, and Germany are its top trading partners.In 2007, vehicles constituted both the leading import and leading export commodity. China is the largest foreign holder of U.S. public debt.
In 2009, the private sector was estimated to constitute 55.3% of the economy, with federal government activity accounting for 24.1% and state and local government activity (including federal transfers) the remaining 20.6%. While its economy has reached a postindustrial level of development and its service sector constitutes 67.8% of GDP, the United States remains an industrial power. The leading business field by gross business receipts is wholesale and retail trade; by net income it is manufacturing. Chemical products are the leading manufacturing field. The United States is the third largest producer of oil in the world, as well as its largest importer. It is the world's number one producer of electrical and nuclear energy, as well as liquid natural gas, sulfur, phosphates, and salt. While agriculture accounts for just under 1% of GDP, the United States is the world's top producer of corn and soybeans. Coca-Cola and McDonald's are the two most recognized brands in the world.
In August 2010, the American labor force comprised 154.1 million people. With 21.2 million people, government is the leading field of employment. The largest private employment sector is health care and social assistance, with 16.4 million people. About 12% of workers are unionized, compared to 30% in Western Europe. The World Bank ranks the United States first in the ease of hiring and firing workers. In 2009, the United States had the third highest labor productivity per person in the world, behind Luxembourg and Norway. It was fourth in productivity per hour, behind those two countries and the Netherlands. Compared to Europe, U.S. property and corporate income tax rates are generally higher, while labor and, particularly, consumption tax rates are lower.
According to the United States Census Bureau, the pretax median household income in 2007 was $49,777. The median ranged from $65,469 among Asian American households to $32,584 among African American households. Using purchasing power parity exchange rates, the overall median is similar to the most affluent cluster of developed nations. After declining sharply during the middle of the 20th century, poverty rates have plateaued since the early 1970s, with 11–15% of Americans below the poverty line every year, and 58.5% spending at least one year in poverty between the ages of 25 and 75. In 2009, 43.6 million Americans lived in poverty.
The U.S. welfare state is one of the least extensive in the developed world, reducing both relative poverty and absolute poverty by considerably less than the mean for rich nations, though combined private and public social expenditures per capita are relatively high. While the American welfare state effectively reduces poverty among the elderly, it provides relatively little assistance to the young. A 2007 UNICEF study of children's well-being in twenty-one industrialized nations ranked the United States next to last.
Between 1947 and 1979, real median income rose by over 80% for all classes, with the incomes of poor Americans rising faster than those of the rich. Since 1980, the United States has witnessed strong increases in productivity, low unemployment, and low inflation. However, income gains since 1980 have been slower than in previous decades, less widely shared, and accompanied by increased economic insecurity. Median household income has increased for all classes since 1980, largely owing to more dual-earner households, the closing of the gender gap, and longer work hours, but growth has been slower and strongly tilted toward the very top . Consequently, the share of income of the top 1%—21.8% of total reported income in 2005—has more than doubled since 1980, leaving the United States with the greatest income inequality among developed nations. The top 1% pays 27.6% of all federal taxes, while the top 10% pays 54.7%.Wealth, like income, is highly concentrated: The richest 10% of the adult population possesses 69.8% of the country's household wealth, the second-highest share among developed nations. The top 1% possesses 33.4% of net wealth. In 2010 the United Nations Development Programme ranked the United States 12th among 139 countries on its inequality-adjusted human development index (IHDI), eight places lower than in the standard HDI.
The United States has been a leader in scientific research and technological innovation since the late 19th century. In 1876, Alexander Graham Bell was awarded the first U.S. patent for the telephone. Thomas Edison's laboratory developed the phonograph, the first long-lasting light bulb, and the first viable movie camera. Nikola Tesla pioneered alternating current, the AC motor, and radio. In the early 20th century, the automobile companies of Ransom E. Olds and Henry Ford popularized the assembly line. The Wright brothers, in 1903, made the first sustained and controlled heavier-than-air powered flight.
The rise of Nazism in the 1930s led many European scientists, including Albert Einstein and Enrico Fermi, to immigrate to the United States. During World War II, the Manhattan Project developed nuclear weapons, ushering in the Atomic Age. The Space Race produced rapid advances in rocketry, materials science, and computers. IBM, Apple Computer, and Microsoft refined and popularized the personal computer. The United States largely developed the ARPANET and its successor, the Internet. Today, 64% of research and development funding comes from the private sector. The United States leads the world in scientific research papers and impact factor. Americans possess high levels of technological consumer goods, and almost half of U.S. households have broadband Internet access. The country is the primary developer and grower of genetically modified food, representing half of the world's biotech crops.