Well, yes, it depends on the assumptions. Honestly, I have no idea how it worked out in the West, as I come from a country where 2 working parents has been the norm already for my grandparents. Maybe there is lack of production, and more employees could produce more, and hence get paid more (in average). On the other hand, (as I think you implied in another reply) there might be too many employees already, wasting time at work, and a lack of consumption. In that case, the only thing that 2 working spouses would cause is a redistribution in income (2-working-parent families would be getting comparatively more money, 1-working-parent families comparatively less).