While news reports may have you believe that subprime loans held by the poor or people with bad credit histories are the primary reason for the recent rise in foreclosures, that is not the full story. The Mortgage Bankers Association released a study that indicates the major driver of defaults in Florida, Nevada, California and Arizona -- the leaders in the race to be the top foreclosure states [subscription] -- are owners who don't live in their properties. In other words, investors are driving the market in those locations, according to a story in the Wall Street Journal today.

The Journal tells the story of two real estate investors, one in Las Vegas, Nevada, and the other in Del Ray, Florida, who both bought multiple homes as real estate investments hoping to flip them quickly for a profit. Now that the bubble has burst, they can't flip the properties and they can't rent them for enough money to cover the mortgage payments.

The Nevada investor is a 40-year-old real estate agent who bought 16 homes hoping that by flipping them he could fund his retirement nest egg. Now he has a total of $45,000 in mortgage payments per month and can't afford them, so he stopped making payments on them and walked away. His credit score dropped from 730 to 400. The Florida investor hasn't walked away from his properties yet, but is planning to do so. He is a 53-year-old air-conditioner contractor who bought four units in a Florida condominium with the hopes of flipping them. His monthly mortgage payments total $4,000.

When I logged onto Amazon.com to check out the new releases in business books, this headline jumped off the page: Real Estate Sale: Save up to 39%.

The headline was followed by this: Whether you're a real estate professional or a first-time home buyer, find all the guides you'll need for becoming a landlord, finding a mortgage, selling properties, and investing in one of the most time-tested and popular strategies for building wealth, all at up to 39% off for a limited time.

Among the deals:

• Flipping Properties: Generate Instant Cash Profits in Real Estate, which is 33% off.
• How to Be a Quick-Turn Real Estate Millionaire, which is 35% off.
• Investing in Duplexes, Triplexes, and Quads, which is 35% off.
• Why We Want You to Be Rich, which is 37% off (this book would be a ripoff at 99% off, in my opinion).

Granted, most books are on sale at Amazon (NASDAQ:AMZN). That's why I love it. But it does seem a bit unusual that they're advertising especially deep discounts on real estate books. One possible conclusion: people aren't buying them. If we go with the theory that the bull market in real estate was in fact a speculative bubble, this makes sense.