What are the issues in using a country's average earnings to determine classification on a world scale?

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Quizplus · Accepted Answer

All of the given options are valid issues to consider when using a country's average earnings as a basis for world-scale classification. The informal and illegal economies of a country cannot be measured accurately, incomes can vary greatly within regions, and there exists a gender pay gap in many countries. These factors can skew the accuracy of the average earnings and therefore the classification system based on it.

What Are the Issues in Using a Country's Average Earnings