Keys等人(2010)的研究表明，FICO分数高于620的抵押贷款借款人比FICO分数低于620的抵押贷款借款人表现更差。这将导致借款人信用评分与业绩之间的单调关系被打破。在20世纪90年代，资产支持证券至少有5个不同的部门陷入困境，包括房屋净值、房屋改善贷款、制造业住房、设备租赁和特许经营商贷款(Claessens, S。， & Ratnovski, 2015)。因此，当观察到不同的评级机构面临自己的问题时，过度依赖信用评级也导致了一些问题。同样的一个例子是Rocht(2009)，他分析了声誉是内生的，市场环境可能随时间而变化的评级动态模型。
In addition to this, all the authors documented that the conduits had been sponsored by banks which had lower economic capital as measured by the ratio of book value to the assets. It was also found by the authors that the investors who were in conduit with the weaker guarantees suffered a number of small losses, which suggested that there isn’t any risk transfer (Back-Simmon, 2011). In addition to this, there are a number of problems. Ashcraft and Schuermann (2008) gave the description of the seven most important informational frictions which are the part of securitization of subprime mortgage credit before the actual financial crises. These frictions though can be generalized to all the scrutinized transactions. This includes a number of asymmetric problems which are between the lender and originator, between the lender and the investors and also between the beneficiary of the invested funds and other asset managers. In addition to this, the flow of asymmetric information between the investors and the issuers lead to the cost funding which was risk-insensitive.
It was documented by Keys et al (2010) that the mortgage borrowers who have their FICO scores above a threshold of 620 performs worse in comparison to the one who have FICO scores below 620. This will lead in disruption of the monotone relationship between the borrower credit scores and the performances. During the times of 1990s, there were at least 5 different sectors of ABS which had been in trouble including home equity, home improvement lending, manufactured housing, leasing of equipments and loans for franchisee(Claessens, S., & Ratnovski, 2015).Thus, excessive reliance on the credit ratings also led to a number of problems when it was observed that the different rating agency faced their own problems. An example of the same is Rocht (2009) who did the analysis of the dynamic model of ratings under which the reputation is endogenous and the environment of market may be varying over time.