When I saw this chart, the one mitigating thing I thought of was company provided health insurance. Surely that makes up for some of the lost salary? Alas, when I checked wikipedia, employer provided health insurance expanded dramatically soon after WWII due to price controls on salaries. (benefits were exempt). [1]
A counter factor is pensions; as we know pensions are quite rare these days.
1. http://en.wikipedia.org/wiki/Health_insurance_in_the_United_...