Note: The R-squares are from cross-sectional OLS regressions of log hourly wages on the 250+ detailed occupation dummies, along with (in all cases) a quartic in age, and dummies for region of the country (using the four major Census regions), marital status, and race/ethnicity (using mutually exclusive categories of white non-Hispanic, black non-Hispanic, Hispanic any race, and other).  The partial R-squares are calculated in the following way:  the log hourly wage and each detailed occupation dummies are separately regressed on the remaining controls (the quartic in age and the dummies for region, marital status, and race/ethnicity).  Using the residuals from these regressions, residual log hourly wages are regressed separately on the residuals from the occupation dummies regressions. The partial R-squares are the R-squares from these regressions.