An early warning system to help lenders detect impending strategic defaults could serve as a blueprint for homeowners considering walking away from their mortgage and that could encourage more strategic defaults.

Strategic defaulters are homeowners who can afford to make mortgage payments, but proactively decide to stop making mortgage payments in order to induce foreclosure.

The strategy has grown in popularity in an uncertain economy with bleak employment prospects, particularly among short term homeowners who are “underwater,” owing more on their mortgages than their homes are worth.

An estimated 25 to 30 percent of all homeowners nationwide are underwater. Among underwater homeowners today, nearly twice as many (27 percent) as a year ago think it is okay to walk away from a mortgage, according to Fannie Mae.

The “Financial Trust Index”, from the University of Chicago Booth School of Business and Kellogg School of Management, estimated strategic defaults accounted for 30 percent of all defaults during the first quarter this year, but an earlier academic study reported defaults on purpose have amounted to 50 percent or more of all defaults in some hard hit areas during the recession’s darkest days.

What could encourage more strategic defaults is “Predicting Strategic Default,” by major credit scoring system architect FICO (Fair Isaac Corp.). It found that contrary to assumptions, strategic defaulters are far from being financially distressed before they decide to walk.

Their behavior puts greater emphasis on the “strategic” as they exhibit far more calculating credit behavior than do truly distressed consumers who can’t make the mortgage.

FICO defined strategic defaulters as borrowers who are underwater on their loans and fell 90 days behind on their mortgage, yet kept up with all their other debts. FICO found that strategic defaulters tend to be more credit management savvy, have higher credit scores, lower revolving balances, fewer instances of exceeding limits on their credit cards and exhibit lower retail credit card usage than others who default on their mortgage.

It’s the kind of resolute behavior necessary to prepare you for credit life after default.

After strategic default your credit score can drop 150 points or more and leave a black mark on your credit report for seven years, FICO says.

A credit score is a numerical rendition of information on your credit report. The FICO score ranges from about 350 to 850 — the higher the number the better your credit score and the better shot you have a the best credit rates and terms.

After any default, credit and insurance available to you will cost you more and the negative credit information will make it tough to even rent a home.

You could also experience a tax hit if the lender forgives the difference, or legal costs if the lender comes after you for any balance if the lender sells the foreclosed home for less than the amount due on the mortgage.

What’s more, Fannie Mae last year announced further punishment for strategic defaulters — you will be barred from Fannie Mae mortgages for seven years.

Ironically, the FICO study also makes it easier for Fannie Mae to prove you are a strategic defaulter.

Given the school of hard knocks you’ll enter in strategic default, cramming on credit behavior before you sign up isn’t a bad move.

FICO’s findings on strategic default behavior reveals:

• Compared to other defaulters, strategic defaulters have not been in their homes very long. To short-timers, a strategic default may be a no-brainer.

If you purchased your home at the height of the boom and suffered a big value hit, you may not recover to the full purchase price of hour home for years, if ever. Since you’ve paid into your investment for only a few years, you have less to lose than long-timers.

Without the burden of mortgage payments you’ll have time to stash away perhaps tens of thousands of dollars before the lender finally forecloses. Later, a cheaper rental will cut your housing costs and build in more savings.

• Strategic defaulters use credit wisely. Fewer than 10 percent of strategic defaulters maxed out their credit cards. More than 35 percent of non-strategic defaulters did likewise.

If you manage to keep existing credit accounts, you’ll have unused credit to fall back on.

• Strategic defaulters shop for new credit card lines before they stop paying their mortgage. In the days of waning equity and fears of job loss, some homeowners used the same strategy to tap home equity before it disappeared or they were out of work.

Stocking up on new credit before defaulting acknowledges credit will be tough to come by after default.

• Those who walk away from their homes and into foreclosure are able to make calculated credit moves because they have higher credit scores. The higher the credit score the more likely the default was strategic. Most strategic defaulters have credit scores above 620. Defaulters with a credit score of 700 or more are more than twice as likely to be strategic.

The higher the credit score before default, the higher the score will be after the 150-plus possible negative credit score hit that comes with foreclosure. For some, that could put access to credit within reach, after just a few years.

While the FICO report does provide a great deal of insight on strategic defaulters’ behavior, you should understand the report was not designed to serve as a blueprint for you if you’ve been considering walking away.

While you may be able to cushion the financial blow with careful planning and a professional or two holding your hand during the ordeal, any default is risky business you’ll live with for some years to come.