Technical Note
WIID companion (May 2021): integrated and standardized series

This document is part of a series of technical notes describing the compilation of a new companion database that complements the World Income Inequality Database (WIID). A previous note described the selection of income distribution series.

Since these series may differ across welfare concepts and other methods used, this technical note describes the second stage, constructing integrated and standardized country series. It provides an update on the procedure used for the May 2021 version of the data.

It discusses all the necessary adjustments conducted to construct the final series for each country, with consistent estimates of the distribution of net income per capita over the entire period for which information is available. This is mainly divided into two stages. First, integrating country series by interlinking series that overlap over time, then using a more general regression-based approach.

Suplementary material files