Credibility Proxies: Speeding

In light of the taxonomy of credibility proxies outlined in the previous posts in this series, one might predict that speeding and other traffic violations would not be admissible as credibility proxies.  Many, many people speed, suggesting that it does not violate social norms to the same degree that theft and prostitution do.  Moreover, like violence, traffic violations don’t have a particularly clear connection to lying other than through the general idea that people who violate laws are more likely to lie.  

The case law bears out this intuition.  As one Ohio appellate court wrote in 2012, “A ‘rule of thumb’ thus should be that convictions which rest on dishonest conduct relate to credibility whereas those of violent or assaultive crimes generally do not; traffic violations, however serious, are in the same category.” State v. Hubbs, 2012 WL 5830616. 

Another appellate court, this one in Michigan, allowed a rape conviction to stand even though the trial court had refused to hear impeachment evidence relating to the victim’s criminal record before even learning what type of prior conviction was involved.  Invoking some of the same doctrinal vagaries in this area that I have attempted to explore in this series of posts, the trial court had explained, “it’s just a silly rule that you can impeach a person who’s been hold up [sic] for shoplifting but you can’t impeach them if they raped or murdered somebody.”  On appeal, the court found the lower court’s error in not even considering the type of prior conviction harmless in part because the prior conviction had been for unlawful use of a motor vehicle. People v. Brooks, No. 287948, 2010 WL 3238922 (Mich. Ct. App. Aug. 17, 2010).  It seems a safe assumption that the appellate court felt the conviction would have been excluded anyway.

 What is interesting about this insistence that motor vehicle violations do not relate to credibility and are thus not appropriate credibility proxies is that there is evidence to the contrary.

One recent paper connects speeding with fraud by CEOs.  In their paper, “Executives’ ‘Off-The-Job’ Behavior, Corporate Culture, and Financial Reporting Risk” forthcoming in the Journal of Financial Economics, Robert Davidson, Aiyesha Dey, & Abbie Smith find that companies in trouble with the SEC for fraud are more likely to have CEOs who have convictions for traffic violations (as well as a smaller number with domestic violence and felony drug convictions – two other categories of conviction not necessarily accepted as credibility proxies).   It’s an interesting paper, and among other things it implies that this criminal behavior may be predictive of fraud. 

Of course, there are many theories about why and how people decide to lie and it is debatable whether the law should be responsive to them (or how that would work as a practical matter).  Still, this vignette suggests that the way that we currently make decisions about credibility proxies – essentially by incorporating intuitions about what type of prior behavior may predict future lying into the common law – may not always align with more data-driven analyses of the subject.

– JSK