This article assesses two secondary data compilations about income inequality – the World Income Inequality Database (WIIDv2c), and the Standardized World Income Inequality Database (SWIIDv4.0) which is based on WIID but with all observations multiply-imputed. WIID and SWIID are convenient and...

Cross-national differences in outcomes are often analysed using regression analysis of multilevel country datasets, examples of which include the ECHP, ESS, EU-SILC, EVS, ISSP, and SHARE. We review the regression methods applicable to this data structure, pointing out problems with the...