Banks are more willing to agree to a sale at a lower cost than a home owner’s mortgage balance in order to avoid having the property fall into foreclosure, which can be more costly for a lender. In the fourth quarter of 2011, there were more than 88,000 short sales, a rise of 15 percent compared to a year prior. In all, short sales made up 10 percent of all home sales sold in the fourth quarter, according to recent data released by RealtyTrac. On the other hand, bank-owned homes dropped 12 percent year-over-year (to 116,000), making up 13 percent of all home sales during the fourth quarter.