What did the average U.K. bank robber take home annually? Criminals themselves may not know because Rickman says there's "no data on the criminals" associated with the heists—not even how many exist or the average number of heist attempts each year.
Yet economic models assume that criminals act rationally if they perceive the rewards outweigh the risks of their actions. To that end the authors did a back-of-the-envelope calculation to roughly quantify what amount might convince a robber to give up his or her life of crime. Factoring in the per-heist, per-robber haul amount, failure rate and capture rate, that number, called the expected net benefit, ended up being £33,545.40 ($52,100)—roughly 125 percent of the average U.K. journalist's annual salary.
"Bank robbers [are] not living in mansions popping champagne—or most of them are not, anyway," Rickman says.
Robbed of data
But not all bank robbers are created equal. A select few methodically plan their work whereas the majority give little thought to minimizing their risks and upping their hauls, says economist Giovanni Mastrobuoni at the University of Turin's College of Carlo Alberto in Italy.
Mastrobuoni specifically took issue with the article's lack of attention to professional bank robbers, who presumably raked in most of the £7.4 million ($11.5 million) robbed from U.K. banks between 2005 and 2008. "The article suggests, for example, that fast-rising security screens mean less money for robbers," Mastrobuoni says, referring to one of the authors' conclusions that the presence of fast-rising security screens—expensive bulletproof screens that rapidly rise up between a lobby and a teller window at the push of a button—reduced a robbery's success by one third. "But I'd argue that the dumb robbers target banks with fast screens while professional ones scope out the place thoroughly before robbing," Mastrobuoni says. "Since they are better in all dimensions, they get more money."
But the researchers' access to the data, although unprecedented, didn't come without catches. "One condition of access to the data was that we did not analyze different banks themselves," Rickman says. Such limitation bars more meaningful analyses, yet smart bank robbers could use them, for example, to find prime targets for their next heist.
Another problem in examining the professionals is a lack of information about them. "That requires two sets of pretty sensitive data to be collected and matched: banks and criminals," Rickman says. With the BBA having a lock on the bank data and the police a hold on criminal data, he notes, his "hunch is that there is no easy way to match these in the U.K."
Economist Hedayeh Samavati of Indiana University–Purdue University Fort Wayne, who studies U.S. bank robbery economics, says the new work underscores the need for more and better data on the matter. She notes that the enterprise is worth the risks because, ultimately, taxpayers and bank customers "end up paying the bills" for bank robbers' actions in public services, bank fees and more.
"This is a sensitive issue for banks, so there isn't much usable data or data sufficient for people to investigate this issue. It's a major problem," Samavati says. "But I think it's worth the costs, both social and otherwise."