Final answer:
Economists calculate GDP using both the expenditure approach and the income approach to provide a comprehensive measurement of economic activity and avoid double-counting.
Step-by-step explanation:
The expenditure approach calculates GDP by summing up all the spending on final goods and services in the economy. This includes consumption by households, investment by businesses, government spending, and net exports.
The income approach, on the other hand, calculates GDP by summing up all the income earned in the economy. This includes wages, salaries, profits, rent, and interest. By incorporating both approaches, economists can ensure that all economic activity is captured and avoid double-counting.
Therefore, the economists calculate GDP using both the expenditure approach and the income approach is to provide a comprehensive and accurate measurement of a nation's economic activity.