What's the biggest hole in mobile banking security? As my colleague Dave Lott reported in January, bankers say it's consumers' lack of protective behavior when using mobile devices. That means you and me.

In response, financial institutions (FI) have implemented controls including inactivity timeouts and multifactor authentication, as noted in Mobile Banking and Payment Practices of U.S. Financial Institutions, which reported the findings of a 2016 Federal Reserve survey.

Baking these controls into mobile apps makes sense because research on consumer behavior suggests that expecting consumers to independently take steps to protect their accounts and data is not realistic. Take as one example: I co-wrote a paper with Joanna Stavins for the Boston Fed reporting the results of our investigation into consumers' responses to the massive Target data breach. We found that while consumers do react to reports of fraud, their reactions can be short-lived. In addition, consumers' opinions may change, but their behavior may not. In other words, considerations aside from security could take priority. (See also a report on the 2012 South Carolina Department of Revenue breach.)

Debit and credit card data for 40 million cards used in Target stores were stolen in late 2013. The breach was widely reported in the news media and caused many financial institutions to reissue cards. Because it was primarily a debit card breach, one might reasonably expect consumers to take a jaundiced view of debit cards after the breach.

And, indeed, that was the case. The Survey of Consumer Payment Choice was in the field at the time of the Target breach. Some consumers answered questions about the security of debit cards before the breach became public. Others answered after.

Consumers who rated card security after the breach rated debit cards more poorly relative to the average rating of the other payment instruments—cash, paper checks, ACH methods, prepaid cards, and credit cards. So in that sense, they reacted to the news.

One year later, consumers in 2014 rated the security of debit cards more poorly both relative to their ratings of other payment instruments and absolutely (that is, a greater percentage of consumers rated debit cards as risky or very risky). In contrast, compared to 2013, the absolute security ratings of cash improved. There was no change in the security ratings of credit cards.

The more important question: Did consumers change their behavior in response to this massive and widely reported data breach? The answer: not according to this survey data. There was no statistically significant change in consumers' method of payment mix in 2014. Debit cards remained the most popular payment instrument among consumers in 2014, accounting for almost one-third of their payments per month.

What does this mean for financial institutions? Realism about my willingness to take action is well placed. You can't count on me.

Photo of Claire Greene By Claire Greene, a payments risk expert in the Retail Payments Risk Forum at the Atlanta Fed