People aren't paying for more cars, housing, education, childcare, and all of the rest just for the hell of it.
Technically, the middle class is spending more for the hell of it, and that's why dead0man has a point.
The middle class chooses to buy inefficient automobiles, which increase the price of oil, and increase the US trade deficit. The middle class chooses to purchase 2500sq ft homes without retiring mortgage debt. The middle class chooses to encourage or allow their children to borrow excessively for college. The middle class demands to fill their houses with cheap Chinese goods.
The middle class consumer is committing financial suicide by embracing inflexible, intransigent consumptive patterns; however, I still see policy as the dominant force nudging people towards fiscal insanity.