The way I see it, it is wrong to say that white workers gain by discrimination against blacks. To take sucha view is to see things only in terms of the distribution of a presumed finite number of jobs and/or other social resources. Indeed that is to share the presuppositions of so many racialised arguments that 'there is not enough to go round'. Starting from the premise of scarcity leads pretty inexorably to rationing, and from there to one or other species of sectionalism, whether based on nationality, race, gender or generational cohort.
Methodolgically it strikes me as an error to take distribution on the market (including the labour market) as the starting point. Before there is a distribution on the market there is production, and it is in the realm of production that the basis for inequality is created.
You can easily enumerate the inequality between black and white workers in distributional terms. But that only tends to mask the substantial inequality between employers and the rest. So Mat states out with the assumption that white workers are better off because they are in a job. But what does that mean? That they are wage slaves who dedicate just a third of their working lives to creating their own means of subsistence, and the rest making a surplus for the class of employers. For this we should be grateful?
It might be marginally better to be exploited than unemployed, in the same way that it would be better to be taken slave than slaughtered by a conquering army. In distributional terms white workers are better of than blacks. But in the prior relation of social production the underlying inequality is the one where one class works to provide the luxury consumption of another. White workers 'gain' only in the minimal sense of having the advantage of a life of wage slavery. -- Jim heartfield