16
The behavioral response of borrowers (or other targets of the decision) places restrictions
on how decisions based on hard information can be made. Having a decision depend entirely upon
the numbers and a transparent decision rule can work, but only if the cost of manipulating the
numbers is sufficiently high relative to the benefit of the preferred outcome.
16
If a firm can raise
its reported assets or sales by a small amount for a small cost, and this will raise its credit rating
and lower its cost of capital sufficiently, it has an incentive to inflate its reported assets or sales.
17
The rules cannot be a direct and transparent function of the hard numbers if the hard numbers are
under the discretionary control of the target of the decision. In this case, the decision maker has an
incentive to make the decision a fuzzy and opaque function of the inputs. The line between an AA
and an A rating can be kept secret or additional sources of soft information can be included.
18
In
16
In the financial crisis of 2008, a large number of investment grade securities defaulted. The magnitude of the defaults
suggested there was a problem with the rating process (see Benmelech and Dlugosz 2009a; Benmelech and Dlugosz
2009b). Observers in industry, academics, and government suggested possible sources of the problem and potential
solutions. What is intriguing is the defaults experience was very different in the corporate bond market (debt of
operating companies) compared to the structured finance market (e.g., RMBS). Defaults in the corporate bond market
spiked in 2009, but the peak is not drastically different than the peak in prior recessions (see Vazza and Kraemer 2016,
Chart 1). The peak in defaults in the structured finance in 2009 is dramatically larger (see South and Gurwitz 2015,
Chart 1). Although the collapse of the housing market hit the structured finance securities harder, this suggests that a
part of the problem with the rating process resides uniquely in the structured finance segment of the market. For an
operating company, a low cost of capital is an advantage but not its only or predominant source of competitive
advantage. For a securitization structure, a lower cost of capital is one of its few source of “competitive advantage.”
Thus, a bank might change which mortgages are placed into a securitization if this change would increase the faction
of the securitization rated AAA and thus lower the cost of capital. An auto-manufacturing firm is unlikely to close
plants or close down a division solely to get a higher credit rating. The costs of altering the business to improve a
credit score are higher and the benefits are (relatively) lower for an operating firm. This may be why we saw relatively
fewer defaults in the corporate bond sector relative to the securitized sector. This issue prompted the credit rating
agencies to consider different rating scales for structured finance versus corporate debt (Kimball and Cantor 2008).
17
Hu, Huang, and Simonov (2017) see the same behavior in the market for individual loans. The theoretical
importance of nonlinearities in the mapping of inputs (hard information) to outputs (decisions) is discussed in Jensen
(2003). In his examples, the incentives to misstate one’s information are smaller if the payoff function is linear. Small
changes in the reported information have only small changes in the manager’s payoff.
18
There may also be strategic reasons to avoid a transparent mapping between the numbers and the credit rating. The
business model of credit rating agencies relies on market participants being unable to replicate the ratings at lower
cost than the agency. If the mapping were a direct function of easily accessible inputs (e.g., the income statement and
balance sheet) and nothing else, some clever assistant finance or accounting professor would figure out the function.
This is one reason that the early credit reporting agencies released only a fraction of their information publicly in the
form of a credit score. For additional fees, users could review a more complete report (Carruthers and Cohen 2010a,
Cohen and Carruthers 2014).