A Framework for Testing the Equality Between the Health Concentration Curve and the 45-Degree Line
Mohamed Khaled, Paul Makdissi, Rami Tabri, Myra Yazbeck
The health concentration curve is the standard graphical tool to depict socioeconomic health inequality in the literature on health inequality. This paper shows that testing for the absence of socioeconomic health inequality is equivalent to testing if the regression function of health on income is a constant function that is equal to average health status. In consequence, any test for parametric specification of a regression function can be used to test for the absence of socioeconomic health inequality (subject to regularity conditions). Furthermore, this paper illustrates how to test for this equality using the Härdle and Mammen (1993) test for correct parametric regression functional form, and applies it to the National Health Survey 2014.
health concentration curves, socioeconomic health inequality, inference