United States - Economy

According to the International Monetary Fund, the U.S. gross domestic product (GDP) of $22.7 trillion constitutes 24% of the gross world product at market exchange rates and over 16% of the gross world product at purchasing power parity (PPP). 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 fifth in the world in nominal GDP per capita and seventh in GDP per capita at PPP. The country has been the world's largest economy since at least 1900.

The United States is the most technologically powerful and innovative nation, especially in artificial intelligence, computers, pharmaceuticals, and medical, aerospace, and military equipment. The nation's economy is fueled by abundant natural resources, a well-developed infrastructure, and high productivity. It has the second-highest total-estimated value of natural resources, valued at US$ 44.98 trillion in 2019, although sources differ on their estimates. Americans have the highest average household and employee income among OECD member states. In 2013, they had the sixth-highest median household income, down from fourth-highest in 2010.

The U.S. dollar is the currency most used in international transactions and is the world's foremost reserve currency, backed by its economy, its military, the petrodollar system and its linked eurodollar and large U.S. treasuries market. Several countries use it as their official currency and in others it is the *de facto* currency. The New York Stock Exchange and Nasdaq are the world's largest stock exchanges by market capitalization and trade volume.

The largest U.S. trading partners are China, the European Union, Canada, Mexico, India, Japan, South Korea, the United Kingdom, and Taiwan. The U.S. is the world's largest importer and the second-largest exporter. It has free trade agreements with several countries, including the USMCA. The U.S. ranked second in the Global Competitiveness Report in 2019, after Singapore. Of the world's 500 largest companies, 124 are headquartered in the U.S.

While its economy has reached a post-industrial level of development, the United States remains an industrial power. It has a smaller welfare state and redistributes less income through government action than most other high-income countries. The United States ranked the 41st highest in income inequality among 156 countries in 2017, and the highest compared to the rest of the developed world. As of January 1, 2023, the United States had a national debt of $31.4 trillion.

### Income and poverty

CBO chart featuring U.S. family wealth between 1989 and 2013. The top 10% of families held 76% of the wealth in 2013 while the bottom 50% of families held 1%. Inequality increased from 1989 to 2013.
Main articles: Income in the United States and Poverty in the United States

Further information: Affluence in the United States and Income inequality in the United States

At $46,625 USD in 2021, American citizens have the highest median income in the world. Despite the fact that they only account for 4.24% of the global population, they collectively possess 30.2% of the world's total wealth as of 2021, the largest percentage of any country. The U.S. also ranks first in the number of dollar billionaires and millionaires in the world, with 724 billionaires (as of 2021) and nearly 22 million millionaires (2021).

Wealth in the United States is highly concentrated; the richest 10% of the adult population own 72% of the country's household wealth, while the bottom 50% own just 2%. Income inequality in the U.S. remains at record highs, with the top fifth of earners taking home more than half of all income and giving the U.S. one of the widest income distributions among OECD members. 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. The United States also has a higher 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.

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. Attempts to combat homelessness include the Section 8 housing voucher program and implementation of the Housing First strategy across all levels of government.

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 2018, 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 federal government's poverty threshold.

### Science, technology, and energy

Main articles: Science and technology in the United States, Science policy of the United States, and Energy in the United States
U.S. astronaut Buzz Aldrin saluting the flag on the Moon during the Apollo 11, 1969. The United States is the only country that has sent manned missions to the lunar surface.
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 and 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. In the early 20th century, factory electrification, the 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. In 2020, the United States was the country with the second-highest number of published scientific papers and second most patents granted, both after China. In 2021, the United States launched a total of 51 spaceflights. (China reported 55.) The U.S. had 2,944 active satellites in space in December 2021, the highest number of any country.

In 1876, Alexander Graham Bell was awarded the first U.S. patent for the telephone. Thomas Edison's research laboratory developed the phonograph, the first long-lasting light bulb, and the first viable movie camera. The Wright brothers in 1903 made the first sustained and controlled heavier-than-air powered flight, and the automobile companies of Ransom E. Olds and Henry Ford popularized the assembly line in the early 20th century. The rise of fascism and Nazism in the 1920s and 30s led many European scientists, such as 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. During the Cold War, competition for superior missile capability ushered in the Space Race between the U.S. and Soviet Union. The invention of the transistor in the 1950s, a key component in almost all modern electronics, led to the development of microprocessors, software, personal computers and the Internet. In 2022, the United States ranked 2nd in the Global Innovation Index.

As of 2019, the United States receives approximately 80% of its energy from fossil fuels. In 2019, the largest source of the country's energy came from petroleum (36.6%), followed by natural gas (32%), coal (11.4%), renewable sources (11.4%) and nuclear power (8.4%). Americans constitute less than 5% of the world's population, but consume 17% of the world's energy. They account for about 25% of the world's petroleum consumption, while producing only 6% of the world's annual petroleum supply. The U.S. ranks as second-highest emitter of greenhouse gases, exceeded only by China.

### Transportation

Main article: Transportation in the United States
The Downtown Connector in Atlanta, Georgia, part of the Interstate Highway System
The United States's rail network, nearly all standard gauge, is the longest in the world, and exceeds 293,564 km (182,400 mi). It handles mostly freight, with intercity passenger service provided by Amtrak to all but four states. The country's inland waterways are the world's fifth-longest, and total 41,009 km (25,482 mi).

Personal transportation is dominated by automobiles, which operate on a network of 4 million miles (6.4 million kilometers) of public roads. The United States has the world's second-largest automobile market, and has the highest vehicle ownership per capita in the world, with 816.4 vehicles per 1,000 Americans (2014). In 2017, there were 255 million non-two wheel motor vehicles, or about 910 vehicles per 1,000 people.

The civil airline industry is entirely privately owned and has been largely deregulated since 1978, while most major airports are publicly owned. The three largest airlines in the world by passengers carried are U.S.-based; American Airlines is number one after its 2013 acquisition by US Airways. Of the world's 50 busiest passenger airports, 16 are in the United States, including the busiest, Hartsfield–Jackson Atlanta International Airport. Of the fifty busiest container ports, four are located in the United States, of which the busiest is the Port of Los Angeles.

References: Wikipedia