  Reliable statistical information is important to make political decisions on
a sound basis and to help measure the impact of policies. Unfortunately,
statistics offices in developing countries have scarce resources and
statistical censuses are therefore conducted sporadically. Based on mobile
phone communications and history of airtime credit purchases, we estimate the
relative income of individuals, the diversity and inequality of income, and an
indicator for socioeconomic segregation for fine-grained regions of an African
country. Our study shows how to use mobile phone datasets as a starting point
to understand the socio-economic state of a country, which can be especially
useful in countries with few resources to conduct large surveys.
