Last week I spent some time collecting some data from various sources that summarise the differences and relationships between various crude measures of national performance, mostly for an introductory class on regression (which according to Rafe is the most fun that you can have with your pants on!). The chart below is the scatterplot of a tragedy and doesn’t require any sophisticated Bayesian modelling or even standard errors to appreciate. It shows the relationship between life-span and GDP across 160 countries. (If you cannot see it properly, the data and the graphic are in the Excel file HERE and you can follow the links to check the exact variable definitions. The file also has some other variables such as the freedom index that you might find interesting.)
There is Ireland, newly joined the leading pack, the reasons for which we may have cause to debate. But they do not live as long as we do (Australia is in red). While there is a fairly strong trend (r-squared about 57%) the effect of higher GDP on life span really tails off after about k$20. If life span is a surrogate for general well being then we would expect a similar graph for well being. So it is probably no surprise that the various non-GDP well being indices show modest improvements in the recent past for effluent countries as they slowly increase their GDP from already high levels.
But what stands out more obviously in this plot is the huge variation in mean life spans at low GDP. There is a bunch of countries that visually seem to be following a quite different trend to the rest. Here is a list of the countries on this plot that have life-spans that fall at least 10 years below the mean for countries at that level of GDP (using log-GDP as predictor of life-span).
|Country||Deviation from GDP trend||Population (1000’s)|
All are in Africa and ten (asterisked) are in southern Africa. It doesn’t take a genius to guess what the common feature is. AIDS. There are over 160 million people in the region and the the loss in potential life is truly staggering Great Leap Forward level staggering. I searched the web but could not find a list of country specific infection or prevalence rates though someone with more time could collate the information at UNAIDS. The ever helpful Wiki has the graphic below and points out that in Southern Africa only Angola has a prevalence rate of less than 10%. Of course this is a superficial analysis which doesn’t take account of other possibly confounding factors.
I do not know much about the politics of AIDS except to say that I am confident it was not a CIA plot to kill off black people. Nor is it a beat up by the drug companies to sell Africa expensive drugs they do not need, as Thabo Mbeki once thought. I do know that the epidemic was completely avoidable because we, and other western countries, avoided it after a significant initial infection. After all. We all know how it is mainly spread. It would only have taken a few billion dollars and a change of heart from the soon to be canonised John Paul 2 who died without giving his papal blessing to the condom.