Aid Watch picks on the new HDR computation methodology
The biggest change in method was that the new HDI is a geometric average rather than a normal (additive) average. Geometric average means you multiply the separate indices (each ranging between 0 and 1) for income, life expectancy, and education together and then take the cube root (I know your pulse starts to race here…)
Now, students, please notice the following: if one of these indices is zero, then the new HDI will be zero, regardless of how great the other indices are. The same mostly applies if one of the indices is close to zero. The new HDI has a “you’re only as strong as your weakest link” property, and in practice the weakest link turns out to be very low income (and guess which region has very low income).
So, as Martin noted, the new HDI relative to the old HDI penalizes countries with very low income compared to decent numbers on life expectancy and education. One reason I think this is unintentional is that these are exactly the cases that the HDR used to celebrate! The biggest losers here are Zimbabwe, Liberia, DR Congo, Burundi, Madagascar, Malawi, Niger, and Togo.
…it’s clear that obscure choices of method make a big difference in who you celebrate – and who you make look bad. And way too often, Africa winds up in the latter category.