The Disturbing "Rise" of Global Income Inequality

I read an article a few months ago in I think the Economist about the findings of the Catalan Economist Xavier Sala-i-Martin about the supposed rise of global inequality that all the anti globalisation people are shouting about. I was reminded of it by an article in the New York Times I received yesterday, so I decided to have a read through Xavier's actual paper.

Now I've never quite been able to believe 100% in this rise, based on what I've seen with my own eyes. But the annual UN Human Development Report that everyone quotes from says it's so.

Xavier has done some detailed analysis of many of the figures in the HDR and has some very suprising things to say about it.

1. In country inequality is generally not rising. Since the seventies there has been a growth of a significant middle class just about everywhere except for Africa.

2. Poverty levels have gone down, within countries. This again is suprising, if you've read the HDR before hand.

3. While the in country differences were reported in the HDR with adjustments for Purchase Power, the across country global figures were not. These figures were based solely on a non PPA adjusted GDP/Capita figure, which I at least was taught in school was not very accurate at all.

4. If you redo the statistics using PPA adjusted figures the global figures show no or little rise at all.

I think this is very interesting, and it shows the importance of globalisation. There can be no doubt at all that tariffs and other protective measures are bad for the people of poor countries.

Xavier mentions Africa as the only real sore spot, where there has been rises in inequalities. This he claims is due to the absolute corruption of many countries. Nigeria being the prime example.

I'm not an Statistician nor an economist, but it all kind of makes sense to me. However if any one else has comments on his figures or methodology please comment here, or email me. I'd like to see it.