According to a recent study, smoking marijuana for many years leads to a severe loss of intelligence: compared with people who did not consume cannabis, the IQ’s of smokers were lower by 13-38 points (Meier et al.: “Persistent cannabis users show neuropsychological decline from childhood to midlife”, PNAS 109, 2012). Moreover, after a long time of consumption, cognitive abilities and memory do not recover when smoking marijuana is eventually given up.

In summer, social media were flooded with videos showing your friends (and celebrities of all levels of prominence) pouring buckets of icy water over their heads. While some people enjoyed watching this (and even participated in the Ice Bucket Challenge), many were unnerved by this charity campaign which was hardly distinguishable from an ordinary spam attack, were it not for the fact that now your friends and acquaintances were spamming you. A third group, however, showed the most interesting reaction: they became moral about it.

When thinking of “market distortions” we typically imagine government regulations, taxes, and subsidies that prevent market mechanisms from achieving an optimal outcome. For example, if you pay $100 for a 30-minute taxi ride (as is the case in many European capitals), you can easily relate it to a government regulation requiring all taxi drivers to be licensed (at a very high cost). In the absence of such a requirement, many more drivers would be able to enter the taxi driving profession, increasing supply and reducing prices.