Criterion used by the World Bank
The main criterion used by the World Bank to classify different countries is their income level. The World Bank classifies countries based on their Gross National Income (GNI) per capita.

Limitations of this criterion
- Does not account for other factors: The income level criterion does not take into account other important indicators such as poverty rates, inequality, access to healthcare and education, and overall standard of living. This means that countries with similar income levels can have vastly different living conditions.
- Does not consider regional disparities: The income level criterion may not accurately reflect regional disparities within a country. For example, a country with a high average income level may still have pockets of poverty and underdevelopment.
- Does not capture non-monetary aspects of development: The income level criterion focuses solely on economic indicators and may not capture important aspects of development such as environmental sustainability, social cohesion, and political stability.
- Subject to fluctuations: GNI per capita can be subject to fluctuations due to factors such as exchange rate changes, inflation, and economic crises. This can lead to countries moving in and out of different income categories, which may not accurately reflect their long-term development status.
In conclusion, while income level is an important criterion used by the World Bank to classify countries, it has limitations in providing a comprehensive picture of a country's development status. It is important to consider other factors and indicators in conjunction with income level to get a more accurate assessment of a country's development.