In high school, I had a job working at a very small tax office: just my boss and me. She was going out of the country for a while, so she asked me to monitor the mail while she was gone for a certain check and to deposit it at the bank.
When the check arrived, I was floored to see that it was for $89,000. I felt nervous handling it, driving it to the bank, and handing it over to the teller. My mom even accompanied me into the bank to make sure that everything went OK.
Of course, the teller accepted the check without batting an eye or calling over a senior manager.
Maybe I was destined to become an economist someday, because I imagined what would happen had I tried to sign the check over to myself. Perhaps it would have been technically impossible to take the money myself, but that didn't stop me from daydreaming about my ill-gotten sportscar and big-screen TV.
But I quickly realized that I couldn't live forever on $89,000, and that I'd have to sacrifice my job, my family (my boss was a good friend of my aunt), and probably all of my future academic and professional opportunities for this one-time score. Not to mention the constant need to look over my shoulder for law enforcement. It simply wasn't worth it.
Why do armored car drivers almost never take the cash for themselves (despite the recent movie)? Why do the millions of cashiers around the world rarely skim off the top? Why could merchants as early as the 11th century trust hired agents with boatloads of valuable goods (as described in Avner Greif's classic paper)?
Economists generally give two explanations:
(1) Workers are paid an efficiency wage. If the market value for carpenters is $20 an hour and I pay someone $35 an hour, that will give my employee a huge incentive to keep that job by not only working hard but also by not jeopardizing his employment by trying to steal from me.
(2) As described in Greif's paper, reputation is crucial. If you screw over one employer, your chances at future employment are vastly undermined. That's why references for job applicants are so important, and why eBay feedback can quickly sort out the good sellers from the bad.