The United States is a highly developed mixed economy. It is the world's largest economy by nominal GDP and the second largest by purchasing power parity (PPP), behind China. It has the world's sixth highest per capita GDP (nominal) and the eighth highest per capita GDP (PPP) as of 2024. The U.S. accounted for 26% of the global economy in 2023 in nominal terms, and about 15.5% in PPP terms. The U.S. dollar is the currency most used in international transactions and is the world's reserve currency, backed by a large U.S. treasuries market, its role as the reference standard for the petrodollar system, and its linked eurodollar. Several countries use it as their official currency and in others it is the de facto currency. Since the end of World War II, the economy has achieved relatively steady growth, low unemployment and inflation, and rapid advances in technology.<br>The American economy is fueled by high productivity, well-developed transportation infrastructure, and extensive natural resources. Americans have the sixth highest average household and employee income among OECD member states. In 2021, they had the highest median household income. The U.S. has one of the world's highest income inequalities among the developed countries. The largest U.S. trading partners are Canada, Mexico, China, Japan, Germany, South Korea, the United Kingdom, Taiwan, India, and Vietnam. The U.S. is the world's largest importer and second largest exporter. It has free trade agreements with several countries, including Canada and Mexico (through the USMCA), Australia, South Korea, Israel, and several others that are in effect or under negotiation. The U.S. has a highly flexible labor market, where the industry adheres to a hire-and-fire policy, and job security is relatively low. Among OECD nations, the U.S. has a highly efficient and strong social security system; social expenditure stood at roughly 30% of GDP.
Top Sectors in United States
Health care in United States
The American system is a mix of public and private insurance. The government provides insurance coverage for approximately 53 million elderly via Medicare, 62 million lower-income persons via Medicaid, and 15 million military veterans via the Veteran's Administration. About 178 million employed by companies receive subsidized health insurance through their employer, while 52 million other persons directly purchase insurance either via the subsidized marketplace exchanges developed as part of the Affordable Care Act or directly from insurers. The private sector delivers healthcare services, with the exception of the Veteran's Administration, where doctors are employed by the government.
Energy in United States
Energy in the United States is obtained from a diverse portfolio of sources, although the majority came from fossil fuels in 2021, as 36% of the nation's energy originated from petroleum, 32% from natural gas, and 11% from coal. Electricity from nuclear power supplied 8% and renewable energy supplied 12%, which includes biomass, wind, hydro, solar and geothermal.Energy figures are measured in BTU, with 1 BTU equal to 1.055 kJ and 1 quadrillion BTU (1 quad) equal to 1.055 EJ. Because BTU is a unit of heat, sources that generate electricity directly are multiplied by a conversion factor to equate them with sources that use a heat engine.
Transportation in United States
The vast majority of passenger travel in the United States occurs by automobile for shorter distances and airplane or railroad for longer distances. Most cargo in the U.S. is transported by, in descending order, railroad, truck, pipeline, or boat; air shipping is typically used only for perishables and premium express shipments. Transportation is the largest source of greenhouse gas emissions in the United States.
Finance in United States
Measured by value of its listed companies' securities, the New York Stock Exchange is more than three times larger than any other stock exchange in the world.As of October 2008, the combined capitalization of all domestic NYSE listed companies was US$10.1 trillion.NASDAQ is another American stock exchange and the world's third-largest exchange after the New York Stock Exchange and Japan's Tokyo Stock Exchange. However, NASDAQ's trade value is larger than Japan's TSE.NASDAQ is the largest electronic screen-based equity securities trading market in the U.S. With approximately 3,800 companies and corporations, it has more trading volume per hour than any other stock exchange. Because of the influential role that the U.S. stock market plays in international finance, a New York University study in late 2014 interprets that in the short run, stocks that affect the willingness to bear risk independently of macroeconomic fundamentals explain most of the variation in the U.S. stock market. In the long run, the U.S. stock market is profoundly affected by shocks that reallocate the rewards of a given level of production between workers and shareholders. Productivity shocks, however, play a small role in historical stock market fluctuations at all horizons in the U.S. stock market.