Median vs Per Capita Income in Africa

CGD’s Anna Diofasi and Nancy Birdsall compiled median income (2011 PPP) data for 144 countries. In the data they find interesting cases of a mismatch between median and per capita incomes:

the median reflects how much the person at the 50th percentile of the income distribution earns (or spends), giving us a better picture of the well-being of a “typical” individual in a given country. Take Nigeria and Tanzania: in 2010, Nigeria’s GDP per capita (at PPP) was $5,123; Tanzania’s stood at only $2,111. This suggests that Nigerians were more than twice as well off as Tanzanians. Yet, if we compare consumption medians, a different picture emerges: a Nigerian at the middle of the income distribution lived on $1.80 a day, while his or her Tanzanian counterpart had 20 cents more to spend, at $2 a day.

I got curious and made maps of median (2011 $$) and per capita (2010 $$) incomes on the Continent.

income differences

What is going on with median incomes in Central Africa from CAR through to Mozambique? Also, what’s up with Zambia?