I've always thought this was a bit of common wisdom in the sophisticated criminal class: bank robberies are not worth it. The risk is very high, the return very low. And now there's an economic study that confirms it.
Ars Technica brings us a summary of the report in the statistics journal Significance. The report began as a work for a British banking trade organization, who wanted some statistics about the addition of security features to banks. While the statisticians were at it, they also decided to analyze bank robbery from the robber's perspective:
The basic problem is the average haul from a bank job: for the three-year period, it was only £20,330.50 (~$31,613). And it gets worse, as the average robbery involved 1.6 thieves. So the authors conclude, "The return on an average bank robbery is, frankly, rubbish. It is not unimaginable wealth. It is a very modest £12,706.60 per person per raid."
"Given that the average UK wage for those in full-time employment is around £26,000, it will give him a modest life-style for no more than 6 months," the authors note. If a robber keeps hitting banks at a rate sufficient to maintain that modest lifestyle, by a year and a half into their career, odds are better than not they'll have been caught. "As a profitable occupation, bank robbery leaves a lot to be desired."
Worse still, the success of a robbery was a bit like winning the lottery, as the standard deviation on the £20,330.50 was £53,510.20. That means some robbers did far better than average, but it also means that fully a third of robberies failed entirely.
(If, at this point, you're thinking that the UK is just a poor location for the bank robbery industry, think again, as the authors use FBI figures to determine that the average heist in the States only nets $4,330.00.)
It's a long way since the days of Pretty Boy Floyd and Bonnie & Clyde. A bank robbery will get you an immediate cash fix, but it's not enough to really pad your nest. For that you have to actually be the guys running the banks, robbing the American people. And there's no real penalty for that anymore.