Income distribution and health: can polarization explain health outcomes better than inequality?


Utilizing data from the China Health and Nutrition Survey (CHNS) from 1991 to 2011, we aim to analyze the effects of income distribution on two risks for chronic diseases: body mass index (BMI) and blood pressure. Unlike the previous studies, we consider two different kinds of indicators of income distribution: inequality and polarization. Different from relative inequality indicators such as the Gini index, which measure income gaps only, the recently developed polarization indicator captures group clustering and social alienation, in addition to income gaps. Our empirical results demonstrate that both BMI and blood pressure are positively correlated with income polarization, while inequality is a weaker predictor of these health outcomes. Thus, polarization, rather than inequality, should be used when analyzing the relationship between health outcomes and income distribution. We also examine the polarization-to-health transmission mechanism using mediation and moderation analytic frameworks. The results suggest that social networks mediate the effect of polarization on BMI and neutralize the effect on blood pressure.

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Fig. 1

Source:Authors’ construction

Fig. 2

Source: Authors’ calculation of the CHNS data collected in 1991, 1993, 1997, 2000, 2004, 2006, 2009, and 2011

Fig. 3

Source: Authors’ calculation of the CHNS data collected in 1991, 1993, 1997, 2000, 2004, 2006, 2009, and 2011

Fig. 4

Source: Authors’ estimation of the CHNS data collected in 1991, 1993, 1997, 2000, 2004, 2006, 2009, and 2011. The figure is based on the estimates of Table 6 in the Appendix. Ranges indicate 95% confidence intervals


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    Data source: National Bureau of Statistics of China (2011),

  2. 2.

    The sample size of each wave is different. For details, see Table 5 in the Appendix.

  3. 3.

    We reported the median value, since the income variable had quite large dispersion and is skewed.


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This research was supported by the National Natural Science Foundation of China (71833003). The authors would like to thank the two anonymous reviewers for their constructive suggestions and comments.

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Correspondence to Dongfang Meng.



See Tables 5, 6 and Fig. 5

Table 5 Sample size in each wave of the survey.
Table 6 Polarization and health.
Fig. 5

Source: authors’ analyses of the CHNS data collected in 1991, 1993, 1997, 2000, 2004, 2006, 2009, and 2011

Scatter plots: polarization and outcomes. a BMI. b Blood pressure.

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Yao, Y., Wan, G. & Meng, D. Income distribution and health: can polarization explain health outcomes better than inequality?. Eur J Health Econ 20, 543–557 (2019) doi:10.1007/s10198-018-1016-9

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  • Income distribution
  • Polarization
  • Inequality
  • BMI
  • Blood pressure
  • China

JEL Classification

  • I14
  • I15
  • D31