Interesting stuff, Archer45.  
The shift to the two-parent working families ... was economically driven?  As in, need more money?  Believe you have to look deeper. Were formerly one-income families facing deprivation, starvation?  No.  See clothes in closets? Yeah. Did most have cars? Sure.  TV, radios, record players and washing machines? Of course.  So...

It was CONSUMPTION-driven.  It was SOCIETY-driven.  It was WANTS-driven, and not only in the economic sense, either.  As the 60s progressed, it was also driven by women who wanted out of the house and into the workplace. If Linda and Louise chose to stay at home, cook, clean and look after kids, they were seen as regressives. Been that way so long now, you might say ...CULTURALLY-driven.