Global Income Inequality and Cost-of-Living Adjustment: The Geary–Allen World Accounts.

Standard ways of measuring real income are known to be inconsistent with consumer preferences. We provide preference-consistent estimates of real income, based on the income-specific price indices that are consistent with nonhomothetic preferences. We find that existing measures, such as Geary, GEKS and GAIA, create systematic biases: the poorer is a country, the more its income is overestimated by these measures. Consequently, international income inequality is underestimated by the same measures.