A few days ago I wrote a long and detailed critique of a Boston Federal Reserve staff study that argued, among other things, that securitization was not a factor in the paucity of loan modifications. The study reached this conclusion based largely on the similar rate of modifications for portfolio and securitized loans. Although the study controls for the effect of the modification in terms of monthly payment, it otherwise assumes all modifications are created equal. But clearly they are not. There is a significant difference in redefault rates for securitized and portfolio loans, and the securitized loan mods perform much worse. This is something the Boston Fed's study cannot explain other than if there is (1) unobserved heterogeneity in the loans or (2) differences in the loan mods.
Finally, the study has a very strange observation that there is a moral hazard problem in principal balance reductions, but apparently not for interest rate reductions: "Balance reductions are appealing to both borrowers in danger of default and those who are not." Therefore, borrowers might default to get principal reductions. Sure, that's right, but everyone would also like a lower interest rate too. I don't see why a principal reduction presents a different level of moral hazard from an interest rate reduction. In terms of net present value, principal and interest rate are interchangeable (yes, there's an interest deduction, and a principal reduction changes the ability to refinance, but that's not the distinction at issue). The bigger factor pushing against principal reductions (other than servicer compensation) is an accounting issue. A principal reduction shows up on the balance sheet immediately. A reduction of interest just reduces future income.