As many Americans begin to realize that it will be many years (if not decades) before their houses are worth what they owe on them, the idea of walking away from your mortgage is going mainstream.

Not surprisingly, the mortgage industry is doing everything it can to prevent this, including telling homeowners that they have a "moral obligation" to pay.

But do they?

Is it okay to walk away from your mortgage for no other reason that it doesn't make financial sense to keep throwing your hard-earned money away?

There's no universal answer here, but in most cases, the answer is "Yes, it's okay to walk away." Importantly, the reason is not that "Wall Street deserves it" or "We've got to teach the banks a lesson" or any of the other retribution logic being thrown around these days.  The reason is that you and your lender engaged in an arms-length transaction in which both parties balanced competing interests and spelled out their obligations in a clear, signed contract. And unless that contract states that you have a "moral obligation to pay," you don't have a moral obligation to pay.

Specifically, when you borrowed money to buy your house, you engaged in a business transaction. The bank or mortgage-lender evaluated the risk of the transaction and concluded that it would was a risk worth taking. To protect its money, the lender also required that you pledge the house as collateral, and it required you to have some equity in the house as an additional cushion. In the event that you didn't pay, the lender retained the right to seize the house, sell it, and pay itself off before you got your equity. The lender loaned you the money because it concluded that this was a smart business decision.

You, meanwhile, also made a business decision. You decided to borrow money to buy your house even though it meant risking your equity, home, and credit rating.

And now it turns out that both of you made a bad decision.

Fortunately, you don't have to fight about what happens next. The contract between you spells everything out: If you stop paying, the lender gets the house. That's it. Unless the contract specifically differentiates between a failure to pay based on hardship (involuntary) and a failure to pay based on a collapse in the value of the house (voluntary), there's no difference. If the lender thought at the beginning that you had a "moral obligation to pay," it would have specified that in the contract.

Now, compare this to a situation in which you DO have a moral obligation to pay: When you borrow money from a friend at no interest, for example, and you promise that friend that you will give him or her every penny back. THAT is a moral obligation to pay. In this case, your friend did not lend you money to make a profit. Your friend loaned you money to help you out--with no collateral or contract other than your promise to pay.

Just because you don't have a moral obligation to pay your mortgage, of course, this doesn't mean it's smart to walk away. That depends on the state in which you live (some states are "recourse" states, in which lenders can go after other assets), as well as many other considerations about your personal situation. You can learn more about that here.