Everyone is saying how a fan caused a major accident at the Tour de France last week. (See video below of the incident.) But as Ronald Coase would say, isn’t the risk of accidents on the Tour de France a “reciprocal problem”? That is, one could just as well argue that the cyclists were as much to blame for the accident as the hapless fan was, since a cyclist riding on the edge of the road knows ahead of time that a fan might obstruct their right of way. Coase’s counter-intuitive theory of reciprocal risks is so versatile and wide-ranging that I have used it to describe “the battle of the replicants” in the original Blade Runner film (see here) as well as the “right to recline” your seat in economy class steerage on commercial flights (see here).