we provide a detailed summary of the methodology used, along
with the main challenges and caveats regarding our estimations at
the end of the paper.
1.A. Market exchange rates
We first look at global income distribution using market exchange
rates, where all national income estimates are compared in constant
2000 U.S. dollars. Figure 1 and Table 1 show the distribution of
world income from 1990 to 2007 according to the global accounting
model, which decomposes national income by population quintiles
and compares those across countries. This includes all individuals
for which data is available, from the poorest quintile in the
Democratic Republic of Congo to the richest quintile in
Luxembourg (see Table 2). Annex 2 provides quintile information
for all countries. The distribution data reveal an incredibly unequal
planet. As of 2007, the wealthiest 20% of mankind enjoyed nearly
83% of total global income compared to the poorest 20%, which
had exactly a single percentage point under the global accounting
model. Perhaps more shocking, the poorest 40% of the global
population increased its share of total income by less than one
percent between 1990 and 2007.
Figure 1. Global Income Distribution by Population Quintiles, 1990- 2007(or latest available) in constant 2000 U.S. dollars
Source: Authors’ calculations using World Bank (2011), UNU-WIDER (2008) and Eurostat (2011)