At first I was a bit confused by this article, and it looked like there was likely a large correlation/causation bias in determining quality.

Especially since the two outcomes they were looking for were IPO and potential for acquisition.

But after thinking a bit more about the topic, I think they have basically determined how to detect tech companies as a proportion of new business registrants per county. (Especially tech companies have a higher potential for some form of exit, over the typical company given the pervasiveness of acqui-hires)

As they said law firms (i.e. firms with the name of the founders in the name) had less positive outcomes.