We perform decompositions and regression analyses that test for the routinization hypothesis and job polarization at the firm level, instead of the aggregate or industry level as in previous studies. Furthermore, we examine the technology-based explanations for routinization and job polarization at the firm level using firm-level R&D as an explanatory variable in the regressions. Our results for the intermediate education group and the routine occupation group are consistent with polarization at the firm level, i.e. disappearing middle due to technological change. These results are robust for accounting for dynamic selection effects
