The Gridded Population of the World (GPW) series, now in its fourth version (GPWv4), models the distribution of human population (counts and densities) on a continuous global surface. Since the release of the first version of this global population grid in 1995, the essential inputs have been population census tables and corresponding geographic boundaries. For GPWv4, population input data are collected at the most detailed spatial resolution available from the results of the 2010 round of censuses, which occurred between 2005 and 2014. The input data are extrapolated to produce population estimates for the years 2000, 2005, 2010, 2015, and 2020. A set of estimates adjusted to national level, historic and future, population predictions from the United Nation's World Population Prospects report are also produced for the set same set of years. GPWv4 is gridded with an output resolution of 30 arc-seconds (approximately 1 km at the equator).
The GPW data collection provides openly-available, licensed under the Creative Commons Attribution 4.0 International License, gridded population data that maintains fidelity to the input census. This is an advantage of GPW because minimally modeled census information may be analyzed in conjunction with other data sets such as land cover without concern for endogeneity, or double counting. See the FAQ page for more details.
Grids are available for population counts, population density, UN-adjusted population counts, UN-adjusted population density, land area, water area and data quality indicators. Additionally, a vector data set of the center point locations (centroids) for each of the input administrative units and a grid of national level numeric identifiers are included in the collection in order to share information about the input data layers.
In order to broaden the applicability of GPWv4, the data collection will be expanded in future releases to include global population grids of Basic Demographic Characteristics (age and sex) estimated for 2010 and urban/rural designations as defined by national statistics offices.
To see the previous version of GPW, visit the GPWv3 data collection.