Though I'm late to the party on noting Paul Krugman's unpacking of the actual U.S. national debt issue and his smacking down of hysteria over it, I do want to add that this is yet another failure point for analogy and metaphor in policy and politics. Krugman notes that the analogy most often used in discussion of national debt is that the country is like a family, the national economy is like a family's budget -- more specifically, the U.S. debt is often explained as a too-large mortgage that this family has taken out, and now must be repaid. And in general, there are broad strokes and similarities, and indeed analogies can at times offer us ways to wrap our heads around unfamiliar concepts: a peloton of cyclists sometimes moves and reacts like a flock of birds or a school of fish, as the small signals of individual movements propagate and translate into smooth movements of the whole. But, as Krugman shows, just because both involve borrowing money doesn't mean the implications of and appropriate actions for one translate to the other.
Basically, the problem is that analogies (and metaphors) aren't predictive: the peloton may act like a school of fish, but that doesn't mean some of the cyclists should be netted and would be tasty grilled with a bit of lemon. (No, really, the meat would be too tough.)
The same goes for so much of business journalism. One company may be like another, true, but that doesn't mean one is the other, and one's future will not be the other's. At this point, no one would honestly say that Facebook is MySpace and the same will happen to both (though both may end up on the ash heap of history) -- but they did.
The same goes for economics. As Krugman demonstrates:
First, families have to pay back their debt. Governments don’t — all they need to do is ensure that debt grows more slowly than their tax base. The debt from World War II was never repaid; it just became increasingly irrelevant as the U.S. economy grew, and with it the income subject to taxation.
Second — and this is the point almost nobody seems to get — an over-borrowed family owes money to someone else; U.S. debt is, to a large extent, money we owe to ourselves.
Fact-based reporting FTW! It's not only lazy, but it's promoting Bad Ideas to allow the implications of an analogy to run unchecked. (Here we have to keep in mind something from user experience research, and tailor our design/writing to the impulses of users/readers; in this case, the natural impulse is to extend forward the path one has been put on.)
Granted, I've been guilty of employing a metaphor or analogy in a news story, sometimes even to amuse myself in the writing. I hope to keep in mind Krugman's takedown, and always ask, when employing such a rhetorical tool, "but what are the differences, and will they matter more?"