The world economy or global economy is the economy of all humans of the world, considered as the international exchange of goods and services that is expressed in monetary units of account. In some contexts, the two terms are distinct "international" or "global economy" being measured separately and distinguished from national economies while the "world economy" is simply an aggregate of the separate countries' measurements. Beyond the minimum standard concerning value in production, use and exchange the definitions, representations, models and valuations of the world economy vary widely. It is inseparable from the geography and ecology of Earth.
It is common to limit questions of the world economy exclusively to human economic activity and the world economy is typically judged in monetary terms, even in cases in which there is no efficient market to help valuate certain goods or services, or in cases in which a lack of independent research or government cooperation makes establishing figures difficult. Typical examples are illegal drugs and other black market goods, which by any standard are a part of the world economy, but for which there is by definition no legal market of any kind.
However, even in cases in which there is a clear and efficient market to establish a monetary value, economists do not typically use the current or official exchange rate to translate the monetary units of this market into a single unit for the world economy since exchange rates typically do not closely reflect worldwide value, for example in cases where the volume or price of transactions is closely regulated by the government.
Rather, market valuations in a local currency are typically translated to a single monetary unit using the idea of purchasing power. This is the method used below, which is used for estimating worldwide economic activity in terms of real United States dollars or euros. However, the world economy can be evaluated and expressed in many more ways. It is unclear, for example, how many of the world's 7.62 billion people have most of their economic activity reflected in these valuations.
According to Maddison, until the middle of 19th century, global output was dominated by China and India. Waves of Industrial Revolution in Western Europe and Northern America shifted the shares to the Western Hemisphere. As of 2017, the following 15 countries or regions have reached an economy of at least US$2 trillion by GDP in nominal or PPP terms: Brazil, China, France, Germany, India, Indonesia, Italy, Japan, South Korea, Mexico, Russia, Turkey, the United Kingdom, the United States and the European Union.
|List of country groups by GDP (nominal) at peak level as of 2019 in millions US$||List of country groups by GDP (PPP) at peak level as of 2019 in millions US$|
|List of the 25 largest economies
by GDP (nominal) at their peak level as of 2019 in millions US$
|List of the 25 largest economies
by GDP (PPP) at their peak level as of 2019 in millions US$
|List of the 25 economies by highest
GDP (nominal) per capita at their peak level as of 2019 in US$
|List of the 25 economies by highest|
GDP (PPP) per capita at their peak level as of 2019 in US$
|1||United States||United States||United States||United States||United States||United States||United States||United States||United States|
|2||Soviet Union||Soviet Union||Japan||Japan||Japan||Japan||China||China||China|
|4||West Germany||West Germany||West Germany||France||Germany||Germany||Germany|
|12||Brazil||Mexico||China||South Korea||South Korea||Mexico||Canada||Spain||South Korea|
|14||Netherlands||Spain||Australia||Netherlands||India||Russia||South Korea||South Korea||Australia|
|19||Switzerland||Switzerland||Sweden||Belgium||Taiwan||Switzerland||Switzerland||Saudi Arabia||Saudi Arabia|
The following is a list of twenty largest economies by GDP based on purchasing power parity at peak value as of the specific year according to the International Monetary Fund and the CIA World Factbook.
|1||United States||United States||United States||United States||United States||United States||United States||China||China|
|2||Soviet Union||Soviet Union||Japan||Japan||China||China||China||United States||United States|
|4||West Germany||West Germany||Soviet Union||Germany||Germany||India||Japan||Japan||Japan|
|14||Saudi Arabia||Iran||Spain||Canada||Canada||Canada||South Korea||South Korea||South Korea|
|15||Indonesia||Indonesia||Saudi Arabia||Saudi Arabia||South Korea||South Korea||Canada||Saudi Arabia||Spain|
|16||Argentina||Saudi Arabia||Turkey||South Korea||Saudi Arabia||Iran||Iran||Canada||Saudi Arabia|
|18||Netherlands||Australia||South Korea||Iran||Iran||Turkey||Saudi Arabia||Iran||Iran|
Telephones - main lines in use: 843,923,500 (2007)
Transportation infrastructure worldwide includes:
To promote exports, many government agencies publish on the web economic studies by sector and country. Among these agencies include the USCS (US DoC) and FAS (USDA) in the United States, EDC and AAFC in Canada, Ubifrance in France, UKTI in the UK, HKTDC and JETRO in Asia, Austrade and NZTE in Oceania. Through Partnership Agreements, the Federation of International Trade Associations publishes studies from several of these agencies (USCS, FAS, AAFC, UKTI and HKTDC) as well as other non-governmental organizations on its website GlobalTrade.net.