Homeowners consistently fail to refinance their mortgages, even when doing so could save them thousands of dollars in interest. This is the finding made by researchers at Columbia Business School whose work was recently published in The Review of Financial Studies. After examining mortgage refinancing data from November 2011 through March 2013, the researchers determined that 51% of homeowners who received preapproval applications through the Home Affordable Refinance Program chose not to apply, a decision which cost them each nearly $9,000 in savings.