It is now generally accepted that when it’s economically irrational for a company to keep paying its debts it will try to renegotiate them or, failing that, default. For creditors, that’s just the price of business. But when it comes to another set of borrowers the norms are very different. The bursting of the housing bubble has left millions of homeowners across the country owing more than their homes are worth. In some areas, well over half of mortgages are underwater, many so deeply that people owe forty or fifty per cent more than the value of their homes. In other words, a good percentage of Americans are in much the same position as American Airlines: they can still pay their debts, but doing so is like setting a pile of money on fire every month.