SN Prime | July 2, 2012 | Vol. 2, No. 25
Hollywood’s versions of heists are typically tales of glamour: A dream team, à la Ocean’s Eleven, meticulously plans and pulls off a multimillion-dollar caper. There are blueprints, elaborate alarm systems (circumvented by even more elaborate electronics), tunnels and false identities. The haul is enormous, permitting the criminals to abandon a life of crime. Well, I have some breaking news: In real life, bank heist stories are much more mundane.
For starters, there’s the take. A new analysis of the economics of bank robberies in the United Kingdom finds that the average yield is a paltry 20,331 pounds, about $30,000. That would barely cover a year’s rent on a studio apartment in New York City, let alone a retirement villa or yacht. In the United States the average haul is even more trifling. According to FBI crime statistics, in 2010 there were 5,628 “bank crime violations” (this includes robberies, burglaries and larcenies, technically different acts). That year’s total loot was $43,016,099.07. Crunch the numbers and the average job brings in $7,643.23.
Of course, averages hide a lot of variation, says economist Neil Rickman of the University of Surrey in England, a coauthor of the analysis. Some robbers are doing it right: The highest take in the U.K. was 425,610 pounds (about $650,000), no small sum. But more telling, one-third of robbers end up empty-handed.
Planning — in the movies and apparently in real life — does improve things. Working as a team ups the take: the researchers found that adding one team member raised the expected value of the proceeds by about 9,000 pounds. (It also means the haul per person goes down, a problem deftly dealt with in The Dark Knight by the Joker, who plucks off his team members one-by-one as their usefulness expires). These gains might reflect expertise: Evidence suggests that experienced robbers operate in teams.
And some robbers know you need to spend money to make money. Investing in a gun can improve expected gains by more than 10,000 pounds. This sum, the researchers note, is a modest reward, given the harsher penalties for armed robbery. Which raises the question of whether someone who robs a bank is thinking rationally. Being economists, Rickman and his colleagues frame robbery as a rational act, conducted only if the expected benefits outweigh the expected costs. The benefits are the loot multiplied by the probability of getting it and keeping it. Costs are just as tidy: Jail time, multiplied by the probability of getting caught and convicted.
The researchers call out this oversimplification, noting that their robbery model is, after all, an economic one. “This assumes, of course, that potential robbers behave rationally and self-interestedly. That people behave thus is a central assumption in economics and is no more true, and no more false, for bank robbers than for anyone else,” the team writes in the June issue of Significance, the magazine of the Royal Statistical Society (a paper presenting the full analysis is in press).
This assumption plagues much of economics, yet reams of research point to situations where rational thought flies the coop. For example, a recent study found that when you last went to the bathroom can influence decision making: offered the choice between a small sum immediately or a larger one later, participants with a full bladder were more likely to hold out for the larger reward. (The researchers speculate that the self-control needed to “hold it in” seeped into — excuse me — the participants’ decisions.)
Other research into robberies suggests rational thinking isn’t often on a would-be robber’s to-do list. A study from the early 1980s that surveyed 157 imprisoned bank robbers found that most didn’t know much about the bank’s security system, with the exception of whether there was a guard. And in 23 percent of the robberies, the robber didn’t even know that. Social variables, such as employment, poverty and education levels, are also thought to play a role in whether someone will rob a bank, though data on how those factors fit in are scant.
Rickman readily acknowledges such nuances. Rationality is only in the eye of the beholder, he notes, as is the value of $7,000. For a beat-down unskilled worker unable to find a job, a drug addict, or any number of people in desperate situations, an impromptu bank robbery may seem like a very good, even rational idea.
Such is the case in one of the best bank heist movies of all time, the Academy Award–winning Dog Day Afternoon. When Sonny (played by Al Pacino) and his friend Sal (played by the late, great John Cazale) attempt to rob a Brooklyn bank they find they’ve arrived after the daily cash pickup, and there’s only $1,000 left. Sonny sets fire to some papers to cover their tracks, the smoke draws attention to the bank and an hours-long standoff ensues. So maybe rational thinking isn’t required for a compelling fictional robbery, either — except that Dog Day Afternoon is based on a true story.
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