Via Overcoming Bias I spotted this paper on global income inequality, 1970-2009. Robin points out to be careful, as this doesn’t capture non-financial inequality, and it doesn’t look at the “lifecycle” of individuals – just snapshots of income dispersion at a point in time. Of course, these missing bits are due to data limitations, the authors would have known this full well.
It shows the global static income inequality has fallen, especially over the last decade. Lovely. However, we only get a small part of the story by looking at that graph – the paper also decomposed changes in the global Gini coefficient into ‘between’, ‘within’, and ‘overlapping’ components. In fact, this decomposition was really the main purpose of the paper!
So let us talk about these things, talk about what happened with them, and see where that leaves us