  Income inequality is a distributional phenomenon. This paper examines the
impact of U.S governor's party allegiance (Republican vs Democrat) on ethnic
wage gap. A descriptive analysis of the distribution of yearly earnings of
Whites and Blacks reveals a divergence in their respective shapes over time
suggesting that aggregate analysis may mask important heterogeneous effects.
This motivates a granular estimation of the comparative causal effect of
governors' party affiliation on labor market outcomes. We use a regression
discontinuity design (RDD) based on marginal electoral victories and samples of
quantiles groups by wage and hours worked. Overall, the distributional causal
estimations show that the vast majority of subgroups of black workers earnings
are not affected by democrat governors' policies, suggesting the possible
existence of structural factors in the labor markets that contribute to create
and keep a wage trap and/or hour worked trap for most of the subgroups of black
workers. Democrat governors increase the number of hours worked of black
workers at the highest quartiles of earnings. A bivariate quantiles groups
analysis shows that democrats decrease the total hours worked for black workers
who have the largest number of hours worked and earn the least. Black workers
earning more and working fewer hours than half of the sample see their number
of hours worked increase under a democrat governor.
