Decomposing Lorenz and Concentration Curves

We decompose the Lorenz curve (LC) and its associated concentration curve (CC) by population subgroups. To illustrate these decompositions, we examine changes in earnings inequality among West Germans, East Germans, and foreign guest workers during the recent German unification. We show that East German earnings have become less concentrated in the lower deciles of the overall German earnings distribution, whereas the earnings of West Germans and foreign guest workers have become more concentrated in the lower deciles