The Penn World Table (PWT) is a set of national-accounts data developed and maintained by scholars at the University of California, Davis and the Groningen Growth Development Centre of the University of Groningen to measure real GDP across countries and over time. [1] [2] Successive updates have added countries (currently 183), years (1950-2019), and data on capital, productivity, employment and population. [3] The current version of the database, version 10, thus allows for comparisons of relative GDP per capita, as a measure of standard of living, the productive capacity of economies and their productivity level. Compared to other databases, such as the World Bank's World Development Indicators, the time period covered is larger and there is more data that is useful for comparing productivity across countries and over time.
A common practice for comparing GDPs across countries has been to use exchange rates. However, this assumes that this relative price – based on traded products – is representative of all relative prices in the economy, i.e. that it represents the purchasing power parity (PPP) of each currency. By contrast, PWT uses detailed prices within each country for different expenditure categories, regardless of whether the output is traded internationally (say, computers) or not (say, haircuts). These detailed prices are combined into an overall relative price level, typically referred to as the country's PPP. The detailed prices used to compute PPPs are based on data published by the World Bank as part of the International Comparison Program (ICP).
An empirical finding documented extensively by PWT is the Penn effect, the finding that real GDP is substantially understated when using exchange rates instead of PPPs in comparing GDP across countries. The most common argument to explain this finding is the Balassa-Samuelson effect, which argues that as countries grow richer, productivity increases mostly in manufacturing and other traded activities. This drives up wages and thus prices of many (non-traded) services, increasing the overall price level of the economy. The result is that poorer countries, such as China, are shown to be much richer based on PPP-converted real GDP than based on exchange-rate-converted GDP.
The database gets its name from the original developers at the University of Pennsylvania, Robert Summers, Irving Kravis and Alan Heston. [4]
Purchasing power parity (PPP) is a measurement of the price of specific goods in different countries and is used to compare the absolute purchasing power of the countries' currencies. PPP is effectively the ratio of the price of a basket of goods at one location divided by the price of the basket of goods at a different location. The PPP inflation and exchange rate may differ from the market exchange rate because of tariffs, and other transaction costs.
The economies of Canada and the United States are similar because both are developed countries. While both countries feature in the top ten economies in the world in 2022, the U.S. is the largest economy in the world, with US$24.8 trillion, with Canada ranking ninth at US$2.2 trillion.
The Balassa–Samuelson effect, also known as Harrod–Balassa–Samuelson effect, the Ricardo–Viner–Harrod–Balassa–Samuelson–Penn–Bhagwati effect, or productivity biased purchasing power parity (PPP) is the tendency for consumer prices to be systematically higher in more developed countries than in less developed countries. This observation about the systematic differences in consumer prices is called the "Penn effect". The Balassa–Samuelson hypothesis is the proposition that this can be explained by the greater variation in productivity between developed and less developed countries in the traded goods' sectors which in turn affects wages and prices in the non-tradable goods sectors.
The Penn effect is the economic finding that real income ratios between high and low income countries are systematically exaggerated by gross domestic product (GDP) conversion at market exchange rates. It is associated with what became the Penn World Table, and it has been a consistent econometric result since at least the 1950s.
Angus Maddison was a distinguished British economist specialising in quantitative macro economic history, including the measurement and analysis of economic growth and development.
Robert Summers was an American economist and professor at the University of Pennsylvania, where he taught from 1960. A widely cited early work by Summers is on the small-sample statistical properties of alternate regression estimators where analytical measures are unavailable.
The international dollar, also known as Geary–Khamis dollar, is a hypothetical unit of currency that has the same purchasing power parity that the U.S. dollar had in the United States at a given point in time. It is mainly used in economics and financial statistics for various purposes, most notably to determine and compare the purchasing power parity and gross domestic product of various countries and markets. The year 1990 or 2000 is often used as a benchmark year for comparisons that run through time. The unit is often abbreviated, e.g. 2000 US dollars or 2000 International$.
Alan W. Heston is an American economist best known for his collaborative work with fellow economist Robert Summers and the development of the Penn World Table (PWT).
The Maddison Project, also known as the Maddison Historical Statistics Project, is a project to collate historical economic statistics, such as GDP, GDP per capita, and labor productivity.
Milton Gilbert was an economist and finance expert who worked at the United States Department of Commerce, Organisation for European Economic Cooperation (OEEC) and Bank for International Settlements.
Irving B. Kravis was an American economist, best known for his work on international price comparisons, leading to the first version of the Penn World Table.
The Total Economy Database describes itself as "a comprehensive database with annual data covering GDP, population, employment, hours, labor quality, capital services, labor productivity, and Total Factor Productivity for 123 countries in the world".
Robert Christopher Feenstra is an American economist, academic and author. He is the C. Bryan Cameron Distinguished Chair in International Economics at University of California, Davis. He served as the director of the International Trade and Investment Program at the National Bureau of Economic Research from 1992 to 2016. He also served as Associate Dean in the Social Sciences at the University of California, Davis from 2014 to 2019.
Inclusive wealth is the aggregate value of all capital assets in a given region, including human capital, social capital, public capital, and natural capital. Maximizing inclusive wealth is often a goal of sustainable development. The Inclusive Wealth Index is a metric for inclusive wealth within countries: unlike gross domestic product (GDP), the Inclusive Wealth Index "provides a tool for countries to measure whether they are developing in a way that allows future generations to meet their own needs".