Melanie Krause, "The Millennium Peak in Club Convergence -- A New Look at Distributional Changes in the Wealth of Nations", Journal of Applied Econometrics, Vol. 32, No. 3, 2017, pp. 621-642. The data were taken from the Penn World Table 8.0, downloaded from www.ggdc.net/pwt. They are contained in the mk-data.txt file. The data are in panel format and consist of 5166 observations, covering 123 countries and 42 years (from 1970 to 2011). The column headers are "countrycode" (ISO 3), "country" (name), "year", "rgdpe" (real gross domestic product at current ppp, expenditure side), "pop" (population), "X" (per capita value of rgdpe), "id" (country id in number). The software consists of various matlab codes, including a main file main.m as well as four others it calls upon: 1) MM_CritBW.m calculates the critical bandwidth for m-modality. 2) MM_Bianchi.m conducts Silverman's (1981) static multimodality test as operationalized by Bianchi (1997) 3) wolfsongini.m calculates both Wolfson's (1992) bi-polarization measure and the Gini coefficient for inequality 4) er_pola.m calculates the polarization measure by Esteban and Ray (2004) The Online Appendix accompanys the publication of the paper in the Journal of Applied Econometrics. It contains additional proofs and large tables. The data file and the four matlab code files are ASCII files in DOS format. They are zipped in the file mk-files.zip. Unix/Linux users should use "unzip -a".