On Income Inequality and Population Size


  • Thitithep Sitthiyot Public Debt Policy Research Division, Policy and Planning Bureau, Public Debt Management Office, Ministry of Finance
  • Kanyarat Holasut Department of Chemical Engineering, Faculty of Engineering, Khon Kaen University




Income Inequality, Gini Coefficient, Population Size


The pursuit of having an appropriate level of income inequality should be viewed as one of the biggest challenges facing academic scholars as well as policy makers. Unfortunately, research on this issue is currently lacking. This study is the first to introduce the theoretical concept of targeted level of income inequality for a given size of population. By employing the World Bank’s data on population size and Gini coefficient from sixty-nine countries in 2012, this study finds that the relationship between Gini coefficient and natural logarithm of population size is nonlinear in the form of a second degree polynomial function. The estimated results using regression analysis show that the majority of countries in the sample have Gini coefficients either too high or too low compared to their appropriate values. These findings could be used as a guideline for policy makers before designing and implementing public policies in order to achieve the targeted level of income inequality.


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How to Cite

Sitthiyot, T., & Holasut, K. (2016). On Income Inequality and Population Size. Thammasat Review of Economic and Social Policy, 2(2), 24–48. https://doi.org/10.14456/tresp.2016.8



Original Articles