In this paper, we employed multivariate econometric analysis approach to study the relationship between taxation and income inequality in Nigeria. The study was a country-specific approach using tax and macroeconomic data from 1980 to 2011. We collected data from the Central Bank of Nigeria Publications, Federal Inland Revenue Service, World Bank and Index Mundi. We estimated the data using a combination of co-integration and error correction model. Preliminary diagnostic analysis using Ramsey RESET test, Breuch-Pagan-Godfrey, Granger causality test and Breuch-Godfrey test of serial correlation were affected to check the accuracy of our model. The preliminary analysis where favourable with no cases of serial correlation, non-normality, bi-directional causality and model misspecification. We found a negative and robust relationship between total tax revenue, total tax revenue to GDP ratio and income inequality in Nigeria with t-values of (-2.748706) and (-2.287270) and negative coefficients of (-0.007869) and (-0.512235) respectively. We found a negative but insignificant relationship between GDPPC, PCREDIT/GDP, TDT/TIT*TTR while LFP and TDT/TIT had positive but insignificant relationship with income inequality with coefficients of (0.421) and (1.243794) and t-values of (1.732565) and (1.717362) respectively.
Keywords: Direct Taxation, Error Correction Model, Granger Causality, Income Inequality, Indirect Taxation, Total Tax Revenue
