If I'd like to study your profile, I'll send you a friend request with full details of what we're doing, and you can 'accept' and opt in, or press 'ignore' and I won't be offended.

BBC: Facebook profile photo experiment goes live

Considering many of the public personalities we venerate, these findings make a lot of sense, though I would like to see a follow on study that examines observer perceptions when the rude rule breakers are caught.

FORBES: Why Absolute Rudeness Impresses Absolutely

Finally, while not detracting from the important contributions of the people acknowledged in Mr Sachs's footnote, I would like to point out that many others contributed to the Bank's study.

ECONOMIST: Growth and geography