Well, you started with a quantitative observation about income figures, but now have shifted to a qualitative (and more subjective) suggestion, that today's two-income families are worse off than the one-income families of the past.

Maybe they are, but it depends a lot on interpretation of whether the 2nd income is a matter of choice or desperation. And, one side effect of women working more is men working less.

For example, in this meta-survey of time allocation across many countries, average 'market hours worked' by women in the USA rose over 4 hours from 1975 to 2003 -- but the same figure for men dropped by over 8 hours. See Table II:

http://papers.ssrn.com/sol3/papers.cfm?abstract_id=1233842

I know that no one household is exactly one average man and one average woman -- but if we imagine that as one possible data point, that household is working less overall, but with more of the working hours carried by the woman, and still earning more in real terms.