Is it possible to gain a rhetorical understanding of the financial crisis? Is it possible that what went wrong, or more realistically, one part of what went wrong was a rhetorical error, a failure of discourse? Was there a problem in the way persuasion operated? We look at things from a rhetorical perspective in order to improve the world by changing communication, changing the ways we are persuaded, by focusing closely on communication and persuasion. Was part of what went wrong in the financial collapse a failure or shortcoming in communication or persuasion. You might think I mean something like, “were borrowers lied to by lenders?” or “were investors lied to by bankers?” But leaving aside lies and dishonesty, what if there was something wrong with the communication or persuasion in the heart of the financial world, something that went wrong not by anyones choice but by the rgular operation of the language of finance. And I don’t mean the potentially obfuscating jargon like ‘sub-prime loans’ or ‘credit default swaps’, those things being too close to the lies mentioned above.
The language of finance is mathematics, or rather mathematics is one of its languages, an Other language, which supplements the jargony discipline-specific uses of English that include ‘sub-prime loans’ or ‘credit default swaps.’ There may be something going on in the regular operation of the language of mathematics that makes finance itself possible. This operation of mathematics-as-language can be addressed by those familiar with mathematics, but if it is indeed language, rhetoricians should also have some insight into it.
A very normal thing happened in the mathematics that supported the finance that “went wrong” in the recent crisis. That very normal thing was that David X. Li constructed, performed into existence, a tentative mathematical structure that gave value to assets… He constructed mathematical entity on top of mathematical entity and in the end, there came to (economic) life an entity that… there emerged a conviction that a numerical valuation of a contract was accurate.
The things he constructed:
- A random variable: In the situation we’re concerned with, we have a bunch of loans that are paying interest. These will stop paying eventually, either because the term expires (and all is well), or because they default. The time each loan takes to stop paying is a random variable. Assuming, for the sake of simplicity that each loan has a term of tf, the time it takes for payments to stop on a loan, Ti, is a random variable with values in (0, tf]. Li calls this random variable for a given loan (asset) its survival time.
- A distribution function for this random variable: The variable itself seems innocuous enough, but since the survival time is a random variable, it has, by mathematical necessity, a distribution function. The distribution function is a curve that tells the probability (y-axis) of payment ending at a given time (x-axis). According to Li, the curve can be constructed using “the market-agreed perception today about the future default tendency of the underlying credit” (10). This is a controversial construction, as indicated by later commentators, e.g. Janet Tavakoli.
- A copula function that gives the joint distribution of several random variables (each related to a defaultable asset/loan) on the basis of their each random variable’s marginal distribution.
- A correlation between the multiple survival time random variables, which is needed for the copula fuction, based on a correlation between the assets/loans in question.
I need to spend more time with 3 and 4 and, likely 2.
Of course, the crucial thing might be that when I say there’s a failure of discourse, it’s not like anyone did anything “wrong.” It’s that this normal operation of mathematical language, the performative construction of some mathematical entities, 1) failed to do what it was intended to do and/or 2) had crazy/destructive effects in spite and in addition to doing what it was intended to do. It isn’t just about lies and deception and greed and bad people. It’s also about uncontrollable math-language.