Timothy E. Goldsmith of New Mexico's Psychology Department and Nathalie Martin at New Mexico's Law School have written Interest Rate Caps, State Legislation, and Public Opinion: Does the Law Reflect the Public's Desires? 89 Chicago-Kent Law Review (2014). Here's the abstract:
In scholarly circles, debates about the benefits and burdens of high-costs lending are prevalent, as are debates about whether to cap interest on certain kinds of consumer loans. Despite this scholarly interest, few scholars actually know what the general public thinks or knows about interest rates on common consumer credit products. This article tries to close this gap through an empirical study of consumer attitudes about interest rates in the state of New Mexico, a state in which high-cost loans such as payday loans and title loans are ubiquitous. Our data show that the general public overwhelmingly supports interest rate caps both in general and for certain types of loans. We also found that many consumers are unaware that there are no interest rate caps on many forms of consumer loans. These data could be useful in explaining why consumers do not do more to change the law on interest rate caps.