[A] brilliant new study ... Zidar and Zwick have some suggestions for how to change this. You might expect them to emphasize access to capital and to higher education, especially for the minority groups they show to be underrepresented among Main Street Millionaires. Instead, they stress connections, networks, and early exposure to entrepreneurs. With starting a business, as with so much else, seeing someone do it makes you likelier to do it yourself ... In the short term, the best we can probably do about this concentration of wealth and power is see it and name it, and that’s what Zidar and Zwick have done. I suspect we will be hearing much more about their work and its implications.