But one of the reasons why it used to be possible for one person to support a family but no longer is is that our standards for what “support a family” means have risen (see also).
If you're willing to be frugal (e.g. spend on yourselves as little as Julia Wise and Jeff Kaufman do) it isn't actually that hard to live on one income in the First World.
That and that when the supply of labor increases, the demand will go down.
Dalrock writes an interesting article related to Dr. Helen Smith's book the Marriage Strike. I really have to bump it up on my too rapidly growing reading list. (^_^)