But please control for confunding factors. Supply-vs-demand in SF and London are rather different, costs of living, union membership statistics, and so on. And even after that you are in for a hard case to argue that unions are responsible for this difference.
And, that said, unions have very bad failure modes, as experienced by the problems with regards to (allegedly?) bad teachers. Also, they are able to mask problems for quite some time, and when they finally implode you have a half-broken sector on your hands with cascading effects and unemployment and defaults and ... well, Detroit-like consequences.
Furthermore, software developers have it good, and probably will be in demand for the coming part of the century, but that won't stop labor exploitation even in the tech sector for specific regions.
And, that said, unions have very bad failure modes, as experienced by the problems with regards to (allegedly?) bad teachers. Also, they are able to mask problems for quite some time, and when they finally implode you have a half-broken sector on your hands with cascading effects and unemployment and defaults and ... well, Detroit-like consequences.
Furthermore, software developers have it good, and probably will be in demand for the coming part of the century, but that won't stop labor exploitation even in the tech sector for specific regions.