By the way, I’ve noticed a “chicken and egg” issue relating to two-income families.
Which came first, or which was the driving force in this transition: Did women enter the work force first, allowing families to buy more goods, or did improved efficiencies such as cheaper and better cars and appliances come first, allowing women to work?
I’m firmly in the workers came first camp. There was a huge one-time bonus here, with families suddenly having more money to chase better houses, buy more cars, etc. This spilled over into massive increases in national productivity and wealth. But once the transition was complete, that was it, people were stuck at that level unless they made very substantial sacrifices, for the cost of good housing had been bid up, they needed two cars and day care, etc. It was too late for families to gracefully back out; the noose was already uncomfortably tight around their necks.
A second wave occurred when outsourcing, etc., meant that labor was now cheaper than ever. Again, during the early days of the transition, it meant huge gains on the consumption side (DVD players were being given away with rebate checks bigger than the cost of the player), and yet profits also flowed back home (albeit substantially into the pockets of CEO's and stock-holders, etc.).
For the same sort of growth spurts to occur again, some new frontier to exploit (or bubble, if you will) must be found. The easy rape of resources is long done. Productivity at home is done. Labor abroad is done in the sense that it is becoming more pricey, not less. I suppose we might hope to profit from improving productivity in developing countries (another one-time spurt at best, though perhaps an extremely powerful one). Who knows, maybe a magic bullet of ubiquitous clean energy?