There is no such thing as local demand for software engineers, instead you get tend to get paid more the bigger the project you work in is. This means that you'

There is no such thing as local demand for software engineers, instead you get tend to get paid more the bigger the project you work in is. This means that you'd expect software engineer salaries to be the highest where you have the highest concentration of them, such as San Francisco or New York. If it becomes illegal to gather such high concentrations of developers in one place then all of those high paying jobs will have to move elsewhere, as you can't sustain them without high concentrations.