A note on estimating income inequality across countries using PPP exchange rates

The use of exchange rates based on Purchasing Power Parities to compare incomes across countries and over time has now become standard practice. But there are reasons to believe that this could lead to excessively inflated incomes for poorer countries and in some cases also inflate the extent of real changes over time. Estimates of gross domestic product growth in the Chinese and Indian economies in recent years provide examples of this.