After all, the argument that Silicon Valley's job hopping fosters innovation contradicts economists' common assumptions. "It didn't feel right to me," James B. Rebitzer, an economist at Case Western Reserve University, said in an interview.
When employees jump from company to company, they take their knowledge with them. "The innovation from one firm will tend to bleed over into other firms," Professor Rebitzer explained. For a given company, "it's hard to capture the returns on your innovation," he went on. "From an economics perspective, that should hamper innovation."
You could write a small book about how this analysis ignores economic units at two scales which are as important as the companies in question: the individuals who are moving around, and Silicon Valley itself. (And yes, there are actors --- from synergy-minded venture capitalists to techies who just like having options --- who have it perfectly well in their interest to think about the economic health of the Valley as a whole). But if you did that, you'd be missing an even more basic mistake: If people were only motivated to do creative work when it was maximizing someone's financial gain, then "starving artist" wouldn't be a cliché.