I love seeing all the speculation here on HackerNews about why tech companies flock to California, and especially to the Bay Area. Everyone has their own theory: access to money, the great weather, non-competes not being enforceable, great universities, the “pay it forward” attitude, immigrant diversity and tolerance, "good" public transit (as compared to other parts of the US), network effect (because the best developers, investors, and tech companies are already there), beautiful landscapes and the ocean, concentration of VCs, etc.

It reminds me of a similarly long discussion here on HN about why Americans were generally thin in the 1950s but much fatter today. Again, everyone was pretty sure of their reason, the leading theories being: fast food, food being cheaper, rise of sedentary jobs, less physical activity due to more cars & labor saving devices, wives now working outside and not cooking at home, big reduction in smoking (because it keeps you thin), more sugar in foods, more carbs in our diet, etc.

All of the theories above sound reasonable. The problem is that there is almost no way to do controlled experiments to find the true answer. And the true answer could be quite complex, like it was initially 38% factor A, 22% factor B, and the C,D, & E making up the rest, but over time it's become 5% factor A, 11% factor B, with factor D now dominating at 58%.

I'm resigned to the conclusion that we're not going to know the answer. It's a complex interaction of millions of individual decisions and interrelated changes over a period of decades in a way that's not reproducible.