Cord shaving has become a greater fear for pay TV operators than cord cutting, since it has a direct impact on the bottom line. Cord cutting can even be given a positive spin as a way of removing the dead wood from bottom end unprofitable subscribers. But now cord shaving appears to be having a direct impact on cable networks as well as the overall operators, at least in the US where the latest data from Nielsen reveals a significant drop in subs for the leading TV networks. The aggregate decline for the 40 leading cable networks is 3.2 million households over four years or 3% of the total audience. ESPN is one of the biggest losers, down 4.5% at…