Stephen J. Dubner: So if your question is when to rob a bank, which plainly is our question — that’s what we titled the book, you think about a few things. You think about, you know, time of day, day of week, part of the year, and so on. And this grew out of the fact that I’d read about a bank robber in New Jersey who was finally arrested after robbing banks on six Thursdays. And it made me wonder maybe Thursday is the best day to rob a bank. Maybe he knew something about the way the bank operated. Maybe that was his day off, whatever. So I went looking into the bank robbery data itself because that’s kind of what we do is look at data and see what’s interesting and this one was more, you know, we weren’t searching for this before the question arose. And so it turns out that the data are kind of fun to play with. It turns out that bank robberies are most — the most common day is Friday, which I guess people, it makes sense because people think it’s payday and there’s a lot of money coming in and going out. But that doesn’t necessarily mean, you know, you’ll be more likely to be successful on Friday. There’s really no big difference in success rates from day of week. But you are much more likely to get more money if you rob a bank in the morning than in the afternoon.
And yet most bank robbers work in the afternoon and not the morning, which leads you to think well either bank robbers aren’t very good at profit maximizing, you know, thinking the way economists do or that maybe they just can’t get up in the morning and go to work bank robbing, which means that maybe if they could get up in the morning early in the first place they wouldn’t have to resort to bank robbery. But the real answer to when to rob a bank is never. And never is the right answer because the ROI or the return on investment on bank robbery is terrible. So if you’re going to become a criminal, bank robbery is a bad crime. The average haul is about $4,000 in the U.S. per bank robbery. In the UK, it’s substantially more, so you could consider that. And you’re likely to get arrested after just three bank robberies and sent to prison. So you have to think as a career move, bank robbery is really dreadful. And then one other tangent that we got involved with on this and looking into bank robberies is internal, you know, inside jobs. And one of the most interesting ones we came across was a woman in Iowa who for years and years and years had been embezzling money from a bank, about $2 million worth. And the bank was actually owned — the president of the bank was her father, interestingly. So I don’t know what the dynamics were there. And the way she was finally caught — and it turns out that she kept two sets of books, which is kind of how you want to embezzle. And she was exhausted when she was caught.
The reason she was exhausted was because she’s worked so hard. She’d never taken a vacation over all those years. And the reason was that she was scared to because if she took a vacation, someone would find that she’d been keeping two sets of books and she would have been found out. So what was interesting is she went to prison for a few years. She was let out. She moved back in with her parents who were obviously very forgiving since it was the dad’s bank that she had kind of put into trouble. And then she went to work with law enforcement. And what I love about this is it’s the classic tale of — only someone who knows how to cheat or how to steal or how to lie or rob would know how to help the good guys catch the bad guys from doing it. So she went to work for law enforcement and they found that one of the best metrics to look for in preventing white collar crime generally in embezzlement, particularly it was people who took, who didn’t take vacations or who took really strange vacations. So if in your firm you see that someone is passing up on their vacation time, you shouldn’t necessarily think of them as just like a super-hard worker or an altruist to your company. You might want to take a look in their drawer and see if they’re keeping a second set of books.