Oil prices, monetary policy and income inequality: the role of education

Purpose This paper examines how oil supply shocks and monetary policy actions jointly affect wage inequality in the US, with a particular focus on the role of education. The study addresses three key questions: (1) how exogenous oil supply shocks influence wage inequality, (2) how exogenous monetary policy shocks shape income distribution, and (3) whether these effects differ within and between education groups, revealing the role of human capital in amplifying or mitigating inequality. Design/methodology/approach The analysis uses quarterly US data from 2000 to 2021. Wage inequality is measured using the Theil index constructed from CPS/BLS weekly earnings of full-time workers aged 25 and above, allowing additive decomposition into within- and between-education components (high school, bachelor's and advanced degree). Identification relies on exogenous oil supply news shocks and exogenous monetary policy shocks. A vector autoregression (VAR) framework is estimated, and impulse response functions trace the dynamic effects of both shocks on inequality over a 10-quarter horizon. Findings The results show that overall wage inequality increased by about 15% over the sample period, with roughly 75% driven by within-education dispersion rather than differences across education levels. Oil supply shocks significantly raise wage inequality, increasing dispersion within high-school and advanced-degree groups and widening inequality between education groups. In contrast, contractionary monetary policy shocks compress wage inequality, with the strongest effects observed among advanced-degree earners and a reduction in between-education wage gaps. Research limitations/implications This study focuses exclusively on the US due to data availability at a quarterly frequency, which limits the generalizability of the findings to other economies with different labor market institutions and energy dependence. Wage inequality is measured using CPS/BLS data for full-time workers, excluding self-employed and part-time workers, who may experience different distributional effects. The analysis is confined to education-based groupings and does not account for other dimensions of inequality, such as race, gender or industry. Finally, while exogenous shock measures are used, the VAR framework captures average dynamic responses and may not fully reflect nonlinearities or structural changes across different economic regimes. Practical implications The findings show that macroeconomic policies have important distributional effects. Oil supply shocks significantly increase wage inequality, especially within high-school and advanced-degree groups, implying that energy price volatility can worsen income dispersion. Policies that reduce exposure to oil shocks—such as energy diversification and strategic reserves—may therefore also help limit inequality. Monetary policy, while aimed at stabilizing inflation and output, affects income distribution as well: contractionary shocks compress wage inequality, particularly among highly educated workers. Since most inequality arises within education groups, education alone is insufficient; complementary labor market and earnings-stabilization policies are needed to mitigate the unequal effects of macroeconomic shocks. Originality/value This study is among the first to jointly analyze oil supply shocks and monetary policy shocks using exogenous identification while decomposing wage inequality by education. By highlighting heterogeneous distributional responses across education groups, the paper provides new insights into how energy shocks and stabilization policies interact with human capital to shape income inequality.