Economy

Economic indicators
Nominal GDP	$20.66 trillion (Q3 2018)
Real GDP growth	3.5% (Q3 2018)
	2.1% (2017)
CPI inflation	2.2% (November 2018)
Employment-to-population ratio	60.6% (November 2018)
Unemployment	3.7% (November 2018)
Labor force participation rate	62.9% (November 2018)
Total public debt	$21.85 trillion (November 2018)
Household net worth	$109.0 trillion (Q3 2018)

According to the International Monetary Fund, the U.S. GDP of $16.8 trillion constitutes 24% of the gross world product at market exchange rates and over 19% of the gross world product at purchasing power parity. The United States is the largest importer of goods and second-largest exporter, though exports per capita are relatively low. In 2010, the total U.S. trade deficit was $635 billion. Canada, China, Mexico, Japan, and Germany are its top trading partners.

From 1983 to 2008, U.S. real compounded annual GDP growth was 3.3%, compared to a 2.3% weighted average for the rest of the G7. 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.

In 2009, the private sector was estimated to constitute 86.4% of the economy. While its economy has reached a postindustrial level of development, the United States remains an industrial power. In August 2010, the American labor force consisted of 154.1 million people (50%). 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. It has a smaller welfare state and redistributes less income through government action than most European nations.

The United States is the only advanced economy that does not guarantee its workers paid vacation and is one of a few countries in the world without paid family leave as a legal right. 74% of full-time American workers get paid sick leave, according to the Bureau of Labor Statistics, although only 24% of part-time workers get the same benefits. In 2009, the United States had the third-highest workforce productivity per person in the world, behind Luxembourg and Norway.

Science and technology

The United States has been a leader in technological innovation since the late 19th century and scientific research since the mid-20th century. Methods for producing interchangeable parts were developed by the U.S. War Department by the Federal Armories during the first half of the 19th century. This technology, along with the establishment of a machine tool industry, enabled the U.S. to have large-scale manufacturing of sewing machines, bicycles, and other items in the late 19th century and became known as the American system of manufacturing. Factory electrification in the early 20th century and introduction of the assembly line and other labor-saving techniques created the system of mass production. In the 21st century, approximately two-thirds of research and development funding comes from the private sector. The United States leads the world in scientific research papers and impact factor.

In 1876, Alexander Graham Bell was awarded the first U.S. patent for the telephone. Thomas Edison's research laboratory, one of the first of its kind, developed the phonograph, the first long-lasting light bulb, and the first viable movie camera. The latter led to emergence of the worldwide entertainment industry. 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 fascism and Nazism in the 1920s and 30s led many European scientists, including Albert Einstein, Enrico Fermi, and John von Neumann, to immigrate to the United States. During World War II, the Manhattan Project developed nuclear weapons, ushering in the Atomic Age, while the Space Race produced rapid advances in rocketry, materials science, and aeronautics.

The invention of the transistor in the 1950s, a key active component in practically all modern electronics, led to many technological developments and a significant expansion of the U.S. technology industry. This, in turn, led to the establishment of many new technology companies and regions around the country such as Silicon Valley in California. Advancements by American microprocessor companies such as Advanced Micro Devices (AMD) and Intel, along with both computer software and hardware companies such as Adobe Systems, Apple Inc., IBM, Microsoft, and Sun Microsystems, created and popularized the personal computer. The ARPANET was developed in the 1960s to meet Defense Department requirements, and became the first of a series of networks which evolved into the Internet.

Income, poverty and wealth

Accounting for 4.24% of the global population, Americans collectively possess 29.4% of the world's total wealth, the largest percentage of any country. Americans also make up roughly half of the world's population of millionaires. The Global Food Security Index ranked the U.S. number one for food affordability and overall food security in March 2013. Americans on average have more than twice as much living space per dwelling and per person as EU residents. For 2017 the United Nations Development Programme ranked the United States 13th among 189 countries in its Human Development Index (HDI) and 25th among 151 countries in its inequality-adjusted HDI (IHDI).

Wealth, like income and taxes, is highly concentrated; the richest 10% of the adult population possess 72% of the country's household wealth, while the bottom half possess only 2%. According to the Federal Reserve, the top 1% controlled 38.6% of the country's wealth in 2016. In 2017, Forbes found that just three individuals (Jeff Bezos, Warren Buffett and Bill Gates) held more money than the bottom half of the population. According to a 2018 study by the OECD, the United States has a larger percentage of low-income workers than almost any other developed nation, largely because of a weak collective bargaining system and lack of government support for at-risk workers. The top one percent of income-earners accounted for 52 percent of the income gains from 2009 to 2015, where income is defined as market income excluding government transfers.

After years of stagnation, median household income reached a record high in 2016 following two consecutive years of record growth. Income inequality remains at record highs however, with the top fifth of earners taking home more than half of all overall income. The rise in the share of total annual income received by the top one percent, which has more than doubled from nine percent in 1976 to 20 percent in 2011, has significantly affected income inequality, leaving the United States with one of the widest income distributions among OECD nations. The extent and relevance of income inequality is a matter of debate.

There were about 567,715 sheltered and unsheltered homeless persons in the U.S. in January 2019, with almost two-thirds staying in an emergency shelter or transitional housing program. In 2011, 16.7 million children lived in food-insecure households, about 35% more than 2007 levels, though only 845,000 U.S. children (1.1%) saw reduced food intake or disrupted eating patterns at some point during the year, and most cases were not chronic. As of June 2018update, 40 million people, roughly 12.7% of the U.S. population, were living in poverty, including 13.3 million children. Of those impoverished, 18.5 million live in deep poverty (family income below one-half of the poverty threshold) and over five million live "in 'Third World' conditions". In 2017, the U.S. states or territories with the lowest and highest poverty rates were New Hampshire (7.6%) and American Samoa (65%), respectively. The economic impact and mass unemployment caused by the COVID-19 pandemic has raised fears of a mass eviction crisis, with an analysis by the Aspen Institute indicating that between 30 and 40 million people are at risk for eviction by the end of 2020.