GDP per capita, constant PPP dollars
Documentation – version 25
Summary documentation of v25
GDP per capita measures the value of everything produced in a country during a year, divided by the number of people. The unit is in international dollars, fixed 2011 prices. The data is adjusted for inflation and differences in the cost of living between countries, so-called PPP dollars. The end of the time series, between 1990 and 2016, uses the latest GDP per capita data from the World Bank, from their World Development Indicators. To go back in time before the World Bank series starts in 1990, we have used several sources, such as Angus Maddison. A simplistic way to combine GDP per capita from multiple sources would be to take the levels of the modern data and just apply the historic growth rates to the modern numbers, thereby estimating our way back in time for each country. Whenever new PPP estimates are released, the countries’ relative positions back in history would change, as the complete time-series would move for all previous years. To avoid this, we have used a couple of cross-country comparisons for earlier years, as documented in version 14 below, including Maddison. We make sure that our historic estimates are not affected by new releases of World Bank data, by adjusting the growth rates between the historic benchmarks and 1990, so that the historical relative levels of countries are maintained. Our time-series continue into the future, based on forecasts from IMF World Economic Outlook 2017, October edition. Economic forecasts are never very reliable, and we do these projections only to visualize an “if-then-scenario”. If the current trends for each country continued up to 2022, and if all countries then converged to a common global (and modest) growth rate of 2,2% per year – what would the world look like? Answering this question visually helps us show how much richer the world would become, even with a modest growth rate. We’re not claiming that this is what will happen.
For transparency, we provide the files that we used to calculate this data, which can be found here. We haven’t had the time to clean up and document all the steps in the process, see our data method overview. If you have any questions about the data or suggestions for how to improve it, you are always very welcome to our data forum.
(For several years we were too busy with other things, and failed to update this documentation. Many versions are simply missing from the list below, but those updates were quite trivial: We just kept updating the end of our long historic trends, with the latest numbers from the World Bank every time they released new data.)
» What was new in version 9 (word)
» Documentation of version 8 (pdf)
» Excel file with data and summary meta-data of version 8 (xlsx)
» Go to the google spreadsheet that contains the “data quality rates” for the indicator (spreadsheet)
» Download documentation of version 3 (pdf) – Version 3 is the version of the indicator before the major revision in 22 december 2008. The indicator is available in the graph, it is called “old version of income per person”