Whether or not a loan backing a commercial mortgage-backed security is paid off once it matures can be gauged by how much the investor is owed on the debt, according to a study from analytics firm Trepp. Trepp broke down the eventual fate of the $30.2 billion in CMBS loans that were due to pay off in 2010. It found "a tight correlation between a loan's debt yield and the likelihood that a loan would pay off." Analysts found that 28% of the loans with yields of 8% or less managed to pay off. That increased to 43% of loans with debt yields between 8% and 10%, and ballooned to 75% of loans with debt yield higher than 14%. Investors would be keen to watch the patterns as more loans are coming due in the years to come. According to Fitch Ratings, $22.5 billion in CMBS loans are set to mature in 2011, but 30% of them failed its refinancing test. And Deloitte Financial Advisory Services reported that more than $1.5 trillion in commercial loans, not necessarily tied to CMBS, will mature by 2014, and the means to finance are all but nonexistent. Write to Jon Prior. Follow him on Twitter: @JonAPrior