This sidewalk shop in Boston sells Honest Tea on the honor system: take one tea and deposit US$1 in the cash box. I stood close to the shop and observed it for about 45 minutes. Everyone paid for their drink. It seems that telling people they’re on the honor system makes their conscience kick in. For most people, anyway. Honor codes at universities are based on this trust, and there’s pretty strong evidence that they work.

But I couldn’t help thinking that if such a shop was on the streets of Nairobi, everything would be stolen in an instant. Please feel free to prove me wrong.