We're evidently the reason that taxis are yellow.UPDATE: It seems I was scooped by Stephen Dubner on the Freakonomics blog by about an hour-and-a-half. I do, however, maintain that I stumbled upon the NYTimes letter independently from Dubner, but not independently from my mother who handed me the Times section with the letter circled. As it were, mom also tipped me off to the Lyon letter (below). On a slightly related note, I've actually started reading Freakonomics start to finish, after reading a bunch of interesting excerpts since it came out. So far, I am extremely impressed with the book--I have a serious uneducated interest in economics--and likewise about the Freakonomics blog.