Inequality in the distribution of income can be beneficial or detrimental for economic growth depending on the level of inequality. This study advocates that when income inequality is low, increase in income inequality increases economic growth, whereas when income inequality is high, increase in income inequality decreases economic growth. The level of inequality that maximizes economic growth is defined as the optimum level of income inequality. This article attempts to determine the optimum level of income inequality for South Asia through an econometric analysis. It uses panel data from Bangladesh, India, Nepal, Pakistan and Sri Lanka, over a 34-year period to undertake a systematic investigation using panel instrumental variables techniques. The results of this study confirm that an optimum level of income inequality does exist, and occurs at a Gini coefficient value of 0.4492. Thus, this research empirically confirms that the relationship between income inequality and economic growth is non-linear. Further calculations show that for an economy that is at the optimum level of income inequality, the per capita gross domestic product can be expected to double within approximately 13 years, provided all other factors are held constant. However, a change in the Gini coefficient by 0.10 units in either direction—higher or lower—away from the optimum level, can increase the number of years for the per capita gross domestic product to double by 55 to 57 years, depending on the method of approximation.
BarroR. J. (2000). Inequality and growth in a panel of countries. Journal of Economic Growth, 5(1), 5–32.
5.
Bangladesh Bureau of Statistics [BBS]. (2011). Bangladesh household income and expenditure survey 2010. Author.
6.
Bangladesh Bureau of Statistics [BBS]. (2017). Bangladesh household income and expenditure survey 2016. Author.
7.
BarroR. J. (2008). Inequality and growth revisited(ADB Working Paper Series on Regional Economic Integration, No. 11).
8.
BreitungJ. (2001). The local power of some unit root tests for panel data. In B. H. Baltagi (Ed.)Advances in econometrics, Volume 15: Nonstationary panels, panel cointegration, and dynamic panels, Emerald Group Publishing Limited, Bingley, (pp. 161–178).
9.
BresciaR. H. (2010). The cost of inequality: Social distance, predatory conduct, and the financial crisis. NYU Annual Survey of American Law, 66(641), 641–726.
10.
Castelló-ClimentA. (2004). A reassessment of the relationship between inequality and growth: What human capital inequality data say?Instituto Valenciano de Investigaciones Económicas.
11.
Castells-QuintanaD. a. (2017). Tracking positive and negative effects of inequality on long-run growth. Empirical Economics, 53(4), 1349–1378.
12.
Charles-CollJ. A. (2010). The optimal rate of inequality: A framework for the relationship between income inequality and economic growth. Munich Personal RePEc Archive. Retrieved July 17, 2018, fromhttps://mpra.ub.uni-muenchen.de/28921/1/MPRA_paper_28921.pdf
13.
Charles-CollJ. A. (2014). Inequality and growth in the context of the Mexican economy: Does inequality matter for growth?(ECINEQ, Society for the Study of Economic Inequality Working Paper Series WP 2014–331).
14.
ChenB.-L. (2003). An inverted-U relationship between inequality and long-run growth. Economics Letters, 78(2), 205–212.
15.
CohenP. (2016). A bigger economic pie, but a smaller slice for half of the U.S. The New York Times. Retrieved July 11, 2018, from https://www.nytimes.com/2016/12/06/business/economy/a-bigger-economic-pie-but-a-smaller-slice-for-half-of-the-us.html
16.
CroixD. d., & DoepkeM. (2003). Inequality and growth: Why differential fertility matters. American Economic Review, 93(4), 1091–1113.
17.
DasS., & BreitungJ. (2005). Panel unit root tests under cross-sectional dependence. Statistica Neerlandica, 59(4), 414–433.
18.
de GregorioJ., LeeJ.-W., LedermanD., & RoubiniN. (2004). Growth and adjustment in East Asia and Latin America. Economía, 5(1), 69–134.
19.
DickeyD. A., & FullerW. A. (1979). Distribution of the estimators for autoregressive time series with a unit root. Journal of the American Statistical Association, 74(366a), 427–431.
20.
DickeyD. A., & FullerW. A. (1981). Likelihood ratio statistics for autoregressive time series with a unit root. Econometrica: Journal of the Econometric Society, 49(4), 1057–1072.
21.
EhrhartC. (2009). The effects of inequality on growth: a survey of the theoretical and empirical literature(ECINEQ Working Paper Series 2009-107).
22.
EndersW. (2015). Applied econometric time series (4th edn.). John Wiley & Sons, Inc.
23.
EngleR. F., & GrangerC. W. (1987). Co-integration and error correction: Representation, estimation, and testing. Econometrica, 55(2), 251–276.
24.
ForbesK. J. (2000). A reassessment of the relationship between inequality and growth. American Economic Review, 90(4), 869–887.
25.
GalorO., & MoavO. (2004). From physical to human capital accumulation: Inequality and the process of development. The Review of Economic Studies, 71(4), 1001–1026.
26.
GrangerC. W. (1969). Investigating causal relations by econometric models and cross-spectral methods. Econometrica, 37(3), 424–438.
27.
GrangerC. W. (1980). Testing for causality, a personal viewpoint. Journal of Economic Dynamics and Control, 2, 329–352.
28.
GrangerC. W. (1981). Some properties of time series data and their use in econometric model specification. Journal of Econometrics, 16(1), 121–130.
29.
GrangerC. W. (1983). Co-integrated variables and error-correcting models. PhD diss., (Discussion Paper 83-13). Department of Economics, University of California at San Diego.
30.
GrangerC. W., & NewboldP. (1974). Spurious regressions in econometrics. Journal of Econometrics, 2, 111–120.
31.
HarrisR. D., & TzavalisE. (1999). Inference for unit roots in dynamic panels where the time dimension is fixed. Journal of Econometrics, 91(2), 201–226.
32.
ImK. S., PesaranM. H., & ShinY. (2003). Testing for unit roots in heterogeneous panels. Journal of Econometrics, 115(1), 53–74.
33.
JohansenS. (1995). Likelihood-based inference in cointegrated vector autoregressive models. Oxford University Press.
34.
KaldorN. (1957). A model of economic growth. The Economic Journal, 67(268), 591–624.
35.
KaoC. (1999). Spurious regression and residual-based tests for cointegration in panel data. Journal of Econometrics, 90(1), 1–44.
36.
KeynesJ. M. (1937). The general theory of employment. The Quarterly Journal of Economics, 51(2), 209–223.
37.
KeynesJ. M. (2007). General theory of employment, interest and money (2007 edn.). Palgrave Macmillan.
38.
KrugmanP. (2008). The return of depression economics and the crisis of 2008. Penguin.
39.
KuznetsS. (1955). Economic growth and income inequality. The American Economic Review, 45(1), 1–28.
40.
LevinA., LinC.-F., & ChuC.-S. J. (2002). Unit root tests in panel data: Asymptotic and finite-sample properties. Journal of Econometrics, 108(1), 1–24.
41.
LewisW. A. (1954). Economic development with unlimited supplies of labour. The Manchester School, 22(2), 139–191.
42.
LütkepohlH., & KrätzigM. (2004). Applied time series econometrics. Cambridge University Press.
43.
MaddalaG. S., & WuS. (1999). A comparative study of unit root tests with panel data and a new simple test. Oxford Bulletin of Economics and Statistics, 61(S1), 631–652.
44.
MilanovicB. (2011). More or less: Income inequality has risen over. Retrieved, 16 July 2018, from http://www.imf.org/external/pubs/ft/fandd/2011/09/pdf/milanovi.pdf
45.
Oxfam. (2016). An economy for the 1%: How privilege and power in the economy drive extreme inequality and how this can be stopped. (Oxfam Briefing Paper No. 210). Retrieved, 11 July 2018, from https://www.oxfam.org/sites/www.oxfam.org/files/file_attachments/bp210-economy-one-percent-tax-havens-180116-summ-en_0.pdf
46.
Oxfam. (2017). Even it up: How to tackle inequality in Vietnam. Oxfam. Retrieved, 11 July 2018, from https://www.oxfam.org/sites/www.oxfam.org/files/file_attachments/bp-vietnam-inequality-120117-en.pdf
47.
PacioliL. (1494). Summa de arithmetica geometria proportioni et proportionalita. Paganini.
48.
PartridgeM. D. (1997). Is inequality harmful for growth? The American Economic Review, 87(5), 1019–1032.
49.
PasinettiL. L. (1962). Rate of profit and income distribution in relation to the rate of economic growth. The Review of Economic Studies, 29(4), 267–279.
50.
PedroniP. (1999). Critical values for cointegration tests in heterogeneous panels with multiple regressors. Oxford Bulletin of Economics and Statistics, 61(S1), 653–670.
51.
PedroniP. (2004). Panel cointegration: Asymptotic and finite sample properties of pooled time series tests with an application to the PPP hypothesis. Econometric Theory, 20(3), 597–625.
52.
PerottiR. (1993). Political equilibrium, income distribution, and growth. The Review of Economic Studies, 60(4), 755–776.
53.
PerssonT., & TabelliniG. (1994). Is inequality harmful for growth? The American Economic Review, 84(3), 600–621.
54.
PhillipsP. C., & PerronP. (1988). Testing for a unit root in time series regression. Biometrika, 75(2), 335–346.
55.
Plato. (1960). The laws(1960 edn.). (A. E. Taylor, Trans.). E.P. Dutton and Co.
56.
RajanR. G. (2011). Fault lines: How hidden fractures still threaten the world economy. Princeton University.
57.
RayD. (2001). Development economics (1st ed.). Oxford University Press.
58.
RicardoD. (1821). The principles of taxation and political economy. JM Dent.
59.
RousseauJ. J. (1762 [2004]). The social contract(Penguin Books - Great Ideas 2004 ed.). (M. Cranston, Trans.)Penguin Books.
60.
SaadatS. Y. (2018). The optimum level of income inequality: Evidence from panel data. Journal of Business Policy Research, 13(1), 78–89.
61.
SlavinS. (1999). All the math you'll ever need: A self-teaching guide (Vol. 148). John Wiley & Sons.
62.
SmithA. (1776). An inquiry into the nature and causes of the wealth of nations. Methuen & Co.
63.
SoltF. (2016). The standardized world income inequality database. Social Science Quarterly, 97.
64.
StiglitzJ. (2009). The global crisis, social protection and jobs. International Labour Review, 148(1–2), 1–13.
65.
TrapeznikovaI. (2019). Measuring income inequality. IZA World of Labor, 462. https://doi.org/10.15185/izawol.462
66.
UN. (2015). Transforming our world: The 2030 agenda for sustainable development. United Nations.
67.
WooldridgeJ. M. (2013). Introductory econometrics: A modern approach (5th ed.). Cengage Learning.
68.
World Bank. (2018). World development indicators. Retrieved, 11 May 2018, from Databank: http://databank.worldbank.org/data/reports.aspx?source=world-development-indicator
