Overconsumption

“The wealthy are spending more now simply because they have more money. But their spending has led others to spend more as well, including middle-income families. If the real incomes of middle-class families have grown only slightly, how have they financed this additional consumption? In part by working longer hours, but mainly by saving less and borrowing more.”

That's borrowed from Krugman's slides, who in turn attributes that to Robert Frank. That may very well be true, judging by personal experience. I still maintain that it's ok to have variable costs with a more or less wide variance as long as you can control it, if need be, and also keep your fixed costs under tight control.