You are right that those who start off being well paid in the working-class tend to buy capital with the differential in pay, and thus move into the middle-clas

You are right that those who start off being well paid in the working-class tend to buy capital with the differential in pay, and thus move into the middle-class upon doing so. But, as such, still realize the gains on the capital side, so the decline on the wage side is not the whole picture for them.