Income Inequality and Population Health in Sub-Saharan Africa: A Test of Income Inequality-Health Hypothesis

Main Article Content

Ibrahim Abidemi Odusanya
Anthony Enisan Akinlo

Abstract

Existing studies have shown that income inequality remains a core determinant of population health. These findings are in line with the Income Inequality-Health Hypothesis (IIHH). However, this assertion remains unclear for Sub-Saharan Africa (SSA), despite the rising trend of income disparity in the region and the vastness of the studies that tested the validity of the IIHH. This inferential study, therefore, examines the effect of income inequality on health for 31 Sub-Saharan African countries from 1995 to 2015 using life expectancy at birth, infant mortality rate, and under-five mortality rate as indicators of population health, as well as the Gini index as a measurement of income inequality. The study employed the Generalized Method of Moments (GMM). We infer that income inequality contributes significantly to poor population health in Sub-Saharan Africa, thereby affirming the validity of the Income Inequality-Health Hypothesis for the region.

Downloads

Download data is not yet available.

Article Details

How to Cite
Odusanya, I. A., & Akinlo, A. E. (2021). Income Inequality and Population Health in Sub-Saharan Africa: A Test of Income Inequality-Health Hypothesis. Journal of Population and Social Studies [JPSS], 29(-), 235 - 254. Retrieved from https://so03.tci-thaijo.org/index.php/jpss/article/view/242032
Section
Articles
Author Biography

Ibrahim Abidemi Odusanya, Olabisi Onabanjo University, Nigeria

Corresponding author

References

• Arellano, M., & Bond, S. (1991). Some tests of specification for panel data: Monte Carlo evidence and an application to employment equations. The Review of Economic Studies, 58(2), 277-297. https://doi.org/10.2307/2297968
• Babones, S. J. (2008). Income inequality and population health: Correlation and causality. Social Science & Medicine, 66(7), 1614-1626. https://doi.org/10.1016/j.socscimed.2007.12.012
• Baeten, S., Ourti, T. V., & van Doorslaer, E. (2013). Rising inequalities in income and health in China: Who is left behind? Journal of Health Economics, 32(6), 1214-1229. http://dx.doi.org/10.1016/j.jhealeco.2013.10.00
• Bakkeli, N. Z. (2016) Income inequality and health in China: A panel data analysis. Social Science & Medicine, 157, 39-47. http://dx.doi.org/10.1016/j.socscimed.2016.03.041
• Biggs, B., Kings, L., Basu, S., & Stuckler, D. (2010). Is wealthier always healthier? The impact of national income level, inequality and poverty on public health in Latin America. Social Science & Medicine, 71(2), 266-273. https://doi.org/10.1016/j.socscimed.2010.04.002
• Birdsall, N., Ross, D., & Sabot, R. (1995). Inequality and growth reconsidered: Lessons from East Asia. The World Bank Economic Review, 9(3), 477-508. https://www.jstor.org/stable/3989851
• Bloom, D. E. & Bowser, D. M. (2008). The population health and income nexus in the Mississippi River Delta Region and beyond. Journal of Health and Human Services Administration, 31(1), 105-123. https://www.jstor.org/stable/25790731
• Blundell, R. & Bond, S. (1998) Initial conditions and moment restrictions in dynamic panel data models. Journal of Econometrics, 87(1), 115–143. https://doi.org/10.1016/S0304-4076(98)00009-8
• Chen, Z. & Meltzer, D. (2008). Beefing up with the Chans: Evidence for the effects of relative income and income inequality on health in China Health and Nutrition Survey. Social Science & Medicine, 66(11), 2206 – 2217. https://doi.org/10.1016/j.socscimed.2008.01.016
• Chiang, T. (1999). Economic transition and changing relation between income inequality and mortality in Taiwan: regression analysis. BMJ, 319, 1162-1165. https://doi.org/10.1136/bmj.319.7218.1162
• Elgar, F. J., Gariépya, G., Torsheim, T., & Currie, C. (2016). Early-life income inequality and adolescent health and well-being. Social Science & Medicine, 174, 197-208. https://doi.org/10.1016/j.socscimed.2016.10.014
• Esmaeili, A., Mansouri, S., & Moshavash, M. (2011). Income inequality and population health in Islamic countries. Public Health, 125(9), 577 - 584. https://doi.org/10.1016/j.puhe.2011.06.003
• Feng, Z., Wang, W. W., Jones, K., & Li, Y. (2012). An exploratory multilevel analysis of income, income inequality and self-rated health of the elderly in China. Social Science & Medicine 75(12), 2481– 2492. http://dx.doi.org/10.1016/j.socscimed.2012.09.028
• Figueiredo, F. W. S., & Adami, F. (2018). Income inequality and mortality due to breast cancer: Evidence from Brazil. Clinical Breast Cancer, 18 (4), 651-658. https://doi.org/10.1016/j.clbc.2017.11.005
• Flegg, A. T. (1979). Role of income inequality in the determination of birth rates. Population Studies, 33(3), 457-477. https://doi.org/10.2307/2173892
• Flegg, A. T. (1982). Inequality of income, illiteracy and medical care as determinants of infant mortality in underdeveloped countries. Population Studies, 36(3), 441 - 458. https://doi.org/10.1080/00324728.1982.10405597
• Gründler, K., & Scheurmeyer, P. (2018). Growth effects of inequality and redistribution: What are the transmission channels? Journal of Macroeconomics, 55, 293-313. https://doi.org/10.1016/j.jmacro.2017.12.001
• Grönqvist, H., Johansson, P., & Niknami, S. (2012). Income inequality and health: Lessons from a refugee residential assignment program. Journal of Health Economics, 31(4), 617-629. https://doi.org/10.1016/j.jhealeco.2012.05.003
• Hamilton, T. G. & Kawachi, I. (2013). Changes in income inequality and health of immigrants. Social Science & Medicine, 80, 57-66. https://doi.org/10.1016/j.socscimed.2012.10.002
• Hill, T. D. & Jorgenson, A. (2018). Bring out your dead! A study of income inequality and life expectancy in the United States, 2000-2010. Health &Place, 49, 1-6. https://doi.org/10.1016/j.healthplace.2017.11.001
• Judge, K. (1995). Income distribution and life expectancy: A critical appraisal. BMJ, 311, 1282-1287. https://doi.org/10.1136/bmj.311.7015.1282
• Judge, K., Mulligan, J.-A., & Benzeval, M. (1998). Income inequality and population health. Social Science & Medicine, 46(4-5), 567-579. https://doi.org/10.1016/S0277-9536(97)00204-9
• Karlsdotter, K., Martín, J. J. M., & del Amo González, M. P. (2012). Multilevel analysis of income, income inequalities and health in Spain. Social Science & Medicine, 74(7), 1099-1106. https://doi.org/10.1016/j.socscimed.2011.12.020
• Kawachi, I. & Kennedy, B. P. (1999). Income inequality and health: Pathways and mechanisms. Health Services Research, 34(1), 215-227. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1088996/
• Kawachi, I., Kennedy, B. P., Lochner, K., & Prothrow-Stitch, D. (1997). Social capital, income inequality, and mortality. American Journal of Public Health, 87, 1491-1498. https://doi.org/10.2105/AJPH.87.9.1491
• Kondo, N., Sembajwe, G., Kawachi, van Dam, R. M., Subramanian, S.V., & Yamagata, Z. (2009). Income inequality mortality and self-rated health: meta-analysis of multilevel studies. BMJ, 339, 1178-1181. https://doi.org/10.1136/bmj.b4471
• Lau, E. W., Schooling, C. M., Tin, K. Y., & Leung, G. M. (2012). Income inequality and cause-specific mortality during economic development. Annals of Epidemiology, 22(4), 285-294. http://dx.doi.org/10.1016/j.annepidem.2012.01.009
• LeClere, F. B., & Soobadar, M.-J. (2000). The effect of income inequality on the health of selected US demographic groups. American Journal of Public Health, 90(12), 1892-1897. https://doi.org/10.2105/AJPH.90.12.1892
• Li, H. & Zhu, Y. (2006). Income, income inequality, and health: Evidence from China. Journal of Comparative Economics, 34(4), 668-693. https://doi.org/10.1016/j.jce.2006.08.005
• Matthew, P. & Brodersen, D. M. (2018). Income inequality and health outcomes in the United States: An empirical analysis. The Social Science Journal, 55(4), 432-442. https://doi.org/10.1016/j.soscij.2018.05.001
• McLeod, C. B., Lavis, J. N., Mustard, C.A., & Stoddart, G.L. (2003). Income inequality, household income, and health status in Canada: A prospective cohort study. American Journal of Public Health, 93(8), 1287-1293. https://doi.org/10.2105/AJPH.93.8.1287
• Mellor, J. M. & Milyo, J. (2002). Income inequality and health status in the United States: Evidence from the current population survey. The Journal of Human Resources, 37(3), 510-539. https://doi.org/10.2307/3069680
• Messias, E. (2003). Income inequality, illiteracy rate, and life expectancy in Brazil. American Journal of Public Health, 93(8), 1294-1296. https://doi.org/10.2105/AJPH.93.8.1294
• Moeller, J., Starkel, R., Quiñonez, C., & Vujicic, M. (2017). Income inequality in the United States and its potential effect on oral health. The Journal of the American Dental Association, 148(6), 361-368. http://dx.doi.org/10.1016/j.adaj.2017.02.052
• Odusanya, I. A. & Agboola, B. (2017). Income, income inequality and health: Evidence from Nigeria. Izvestiya Journal of Varna University of Economics, 61(4), 345-361. http://journal.ue-varna.bg/uploads/20180309062942_8481015625aa229d660273.pdf
• Odusanya, I. A. & Atanda, A. A. (2018). Income-health nexus in Sub-Saharan Africa: Evidence from heterogeneous panel models. The European Journal of Applied Economics, 15(1), 94-109. http://journal.singidunum.ac.rs/files/2018-15-1/income-health-nexus-in-sub-saharan-africa-evidence-from-heterogeneous-panel-models.pdf
• Pampel, F. C., & Pillai, V. K. (1986). Patterns and determinants of infant mortality in developed nations, 1950-1975. Demography, 23, 525-542. https://doi.org/10.2307/2061349
• Pasqualini, M., Lanari, D., Minelli, L., Pieroni, L., & Salmasi, L. (2017). Health and income inequalities in Europe: What is the role of circumstances? Economics & Human Biology, 26, 164-173. http://dx.doi.org/10.1016/j.ehb.2017.04.002
• Pop, I. A., van Ingen, E., & van Oorschot, W. (2013). Inequality, wealth and health: Is decreasing inequality the key to create healthier societies? Social Indicators Research, 113, 1025-1043. https://link.springer.com/article/10.1007/s11205-012-0125-6
• Pritchett, L. & Summers, L. H. (1996). Wealthier is healthier. The Journal of Human Resources, 31(4), 841-868. https://doi.org/10.2307/146149
• Qi, Y. (2012). The impact of income inequality on self-rated general health: Evidence from a cross-national study. Research in Social Stratification and Mobility, 30(4), 451-471. https://doi.org/10.1016/j.rssm.2012.07.002
• Rajan, K., Kennedy, J., & King, L. (2013). Is wealthier always healthier in poor countries? The health implications of income, inequality, poverty, and literacy in India. Social Science & Medicine, 88, 98-107. http://dx.doi.org/10.1016/j.socscimed.2013.04.004
• Ram, R. (2005). Income inequality, poverty, and population health: Evidence from recent data for the United States. Social Science & Medicine, 61(12), 2568-2756. https://doi.org/10.1016/j.socscimed.2005.04.038
• Ram, R. (2006). Further examination of the cross-country association between income inequality and population health. Social Science & Medicine 62(3), 779-791. https://doi.org/10.1016/j.socscimed.2005.06.034
• Rasella, D., Aquino, R., & Barreto, M. L. (2013). Impact of income inequality on life expectancy in a highly unequal developing country: the case of Brazil. Journal of Epidemiology & Community Health, 67, 661-666. http://doi.org/10.1136/jech-2012-201426
• Ribeiro, W. S., Bauer, A., Andrade, M. C. R., York-Smith, M., Pan, P.M., Pingani, L., Knapp, M., Coutinho, E. S. F., & Evans-Lacko, S. (2017). Income inequality and mental illness-related morbidity and resilience: A systematic review and meta-analysis. The Lancet Psychiatry, 4(7), 554-562. http://dx.doi.org/10.1016/S2215-0366(17)30159-1.
• Rodgers, G. B. (1979). Income and inequality as determinants of mortality: An international cross-section analysis. Population Studies, 33(2), 343-351. https://doi.org/10.1080/00324728.1979.10410449
• Roodman, D. (2009). How to do Xtabond2: An introduction to Difference and System GMM in Stata. The Stata Journal, 9(1), 86-136. https://doi.org/10.1177/1536867X0900900106
• Ross, N. A., Wolfson, M. C., Dunn, J. R., Berthelot, J.-M., Kaplan, G.A., & Lynch, J. W. (2000). Relation between income inequality and mortality in Canada and in the United States: cross-sectional assessment using census data and vital statistics. BMJ, 320, 898-902. https://doi.org/10.1136/bmj.320.7239.898
• Rözer, J. J. & Volker, B. (2015). Does income inequality have lasting effects on health and trust? Social Science & Medicine, 149, 37-45. https://doi.org/10.1016/j.socscimed.2015.11.047
• Safaei, J. (2007). Income and health inequality across Canadian Provinces. Health & Place, 13(3), 625-638. https://doi.org/10.1016/j.healthplace.2006.09.003
• Shi, L., Macinko, J., Starfield, B., Xu, J., & Politzer, R. (2003). Primary care, income inequality, and stroke mortality in the United States: A longitudinal analysis, 1985-1995. Stroke, 34(8), 1958-1964. https://doi.org/10.1161/01.STR.0000082380.80444.A9
• Shibuya, K., Hashimoto, H., & Yano, E. (2002). Individual income, income distribution, and self-rated health in Japan: cross-sectional analysis of nationally representative sample. BMJ, 324, 16-19. https://doi.org/10.1136/bmj.324.7328.16
• Siddiqi, A., Jones, M. K., & Erwin, P. C. (2015). Does higher income inequality adversely influence infant mortality rates? Reconciling descriptive patterns and recent research findings. Social Science & Medicine, 131, 82-88. http://dx.doi.org/10.1016/j.socscimed.2015.03.010
• Solt, F. (2016). The Standardized World Income Inequality Database. Social Sciences Quarterly, 97(5), 1267-1281. https://doi.org/10.1111/ssqu.12295
• Subramanian, S. V. & Kawachi, I. (2004). Income inequality and health: What have we learned so far? Epidemiologic Review, 26(1), 78-91. https://doi.org/10.1093/epirev/mxh003
• Subramanian, S. V., Kawachi, I., & Smith, G. D. (2007). Income inequality and the double burden of under- and overnutrition in India. Journal of Epidemiology & Community Health, 61(9), 802-809. http://dx.doi.org/10.1136/jech.2006.053801
• Sun, P., Unger, J. B., Palmer, P., Ma, H., Xie, B., Sussmen, S., & Johnson, C. A. (2012). Relative income inequality and selected health outcomes in urban Chinese youth. Social Science & Medicine, 74(1), 84-91. https://doi.org/10.1016/j.socscimed.2011.10.010
• Torre, R. & Myrskylä, M. (2011). Income inequality and population health: a panel data analysis on 21 developed countries. MPIDR Working Paper 2011-006, 1-31. Max Planck Institute for Demographic Research, Germany. https://www.demogr.mpg.de/papers/working/wp-2011-006.pdf
• Undurraga, E. A., Behrman, J. R., Leonard, W. R., & Godoy, R. A. (2016). The effects of community income inequality on health: Evidence from a randomized control trial in the Bolivian Amazon. Social Science & Medicine, 149, 66-75. http://dx.doi.org/10.1016/j.socscimed.2015.12.003
• UNDP. (2017). Income Inequality Trends in Sub-Saharan Africa Divergence, Determinants and Consequences. Eds. Odusola, A., Cornia, G., Bhorat, H. & Conceição, P. A publication of United Nations Development Programme (UNDP). https://www.africa.undp.org/content/rba/en/home/library/reports/income-inequality-trends-in-sub-saharan-africa--divergence--dete.html
• United Nations. (2017). World Mortality Report, 2015. United Nations.
• https://www.un.org/en/development/desa/population/publications/pdf/mortality/WMR2017/WMR2017_Highlights.pdf
• United Nations. (2017). World Mortality 2017: Data Booklet. United Nations. https://www.un.org/en/development/desa/population/publications/pdf/mortality/World-Mortality-2017-Data-Booklet.pdf
• Vilda, D., Wallace, M., Dyer, L., Harville, E., & Theall, K. (2019). Income inequality and racial disparities in pregnancy-related mortality in the US. SSM-Population Health, 9, 100477. https://doi.org/10.1016/j.ssmph.2019.100477
• Vincens, N. & Stafström, M. (2015). Income inequality, economic growth and stroke mortality in Brazil: Longitudinal and regional analysis 2002-2009. PLoS ONE, 10(9), 1-12. https://doi.org/10.1371/journal.pone.0137332
• Walberg, P., Mckee, M., Shkolnikov, V., Chenet, L., & Leon, D. A. (1998). Economic change, crime, and mortality crisis in Russia: regional analysis. BMJ, 317, 312-318. https://doi.org/10.1136/bmj.317.7154.312
• Wen, M., Browning, C. R., & Cagney, K. A. (2003). Poverty, affluence, and income inequality: neighborhood economic structure and its implications for health. Social Science & Medicine, 57(5), 843-860. https://doi.org/10.1016/S0277-9536(02)00457-4
• Wennemo, I. (1993). Infant mortality, public policy and inequality - a comparison of 18 industrialized countries 1950-85. Sociology of Health & Illness, 15(4), 429-446. https://doi.org/10.1111/j.1467-9566.1993.tb00354.x
• Wilkinson, R. G. (1992). Income distribution and life expectancy. BMJ, 304, 165-168. https://doi.org/10.1136/bmj.304.6820.165
• Wilkinson, R. G. & Pickett, K. E. (2006). Income inequality and population health: A review of and explanation of the evidence. Social Science & Medicine, 62(7), 1768-1784. https://doi.org/10.1016/j.socscimed.2005.08.036
• Wolfson, M. C., Kaplan, G., Lynch, J., Ross, N., & Backland, E. (1999). Relation between income inequality and mortality: Empirical demonstration. BMJ, 319, 953-955. https://doi.org/10.1136/bmj.319.7215.953