GIRD: A Multi-Country Database of Income Inequality Dynamics
Research Objective: The goal of this project was to build a “live” open-access database that allows researchers to retrieve, free of charge, a large number of harmonized statistics about cross-sectional income inequality, longitudinal income volatility and intra- and inter-generational income mobility for many countries, many years, and many sub-populations.
Data: The result is the Global Repository of Income Dynamics (GRID), a new open-access, cross-country database that contains a wide range of micro statistics on income inequality, dynamics, and mobility. It has four key characteristics: it is built on micro panel data drawn from administrative records; it fully exploits the longitudinal dimension of the underlying datasets; it offers granular descriptions of income inequality and income dynamics for finely defined sub-populations; and it is designed from ground up with the goals of harmonization and cross-country comparability. There are currently 13 countries in GRID: Argentina, Brazil, Canada, Denmark, France, Germany, Italy, Mexico, Norway, Spain, Sweden, UK, and US. The plan is to expand the coverage of GRID to 25+ countries in the very near future All GRID statistics (tens of thousands are available for download for each country) are computed from longitudinal administrative micro data, either from tax-return or from social security administration records.
Challenges: An important goal of the project is to produce statistics that are as comparable as possible across countries. Harmonization is an inherently challenging task given the differences in variable definitions and data collection methods in different countries. We have spent a great deal of effort to harmonize the statistics taking as given the underlying datasets. An important feature of the project that allows further harmonization is that all statistics for all countries are produced by one unique master code that runs in Stata. This master code generates the full list of statistics we have compiled (about 1.5M data points per country).
Findings: The findings for each of the 13 countries are contained in a Special Issue of Quantitative Economics: Global Income Dynamics. Included is an introductory article from the three project leaders, Fatih Guvenen (U of Minnesota), Luigi Pistaferri (Stanford) and Gianluca Violante (Princeton): Global Trends in Income Inequality and Income Dynamics: New Insights from GRID.