At one level this should come as no surprise. For most of the last decade America was a nation of borrowers and spenders, not savers. The personal savings rate dropped from 9 percent in the 1980s to 5 percent in the 1990s, to just 0.6 percent from 2005 to 2007, and household debt grew much faster than personal income. Why should we have expected our net worth to go up?

Yet until very recently Americans believed they were getting richer, because they received statements saying that their houses and stock portfolios were appreciating in value faster than their debts were increasing. And if the belief of many Americans that they could count on capital gains forever sounds naïve, it’s worth remembering just how many influential voices — notably in right-leaning publications like The Wall Street Journal, Forbes and National Review — promoted that belief, and ridiculed those who worried about low savings and high levels of debt.