Question

why is per capita income calculated in diollars

Answer 1

The per capita income of all the countries are calculated in dollarsbecause.. 2. It is the largest used currency in the world. ... 4.The common currency system taking dollaras the base was devised to bring an homogeneity for studying the GDP of all countries with the same base.

Answer 2

this is done inorder to ease the calculations done to determine a country's GDP, per capita income etc.
One more thing is kept in consideration that these values are taken in Such a way that 1 dollar can buy same amount of goods in any corner of the world
HOPE IT HELPS