They are selecting for people who are fine working in their free time. If you contribute to open source you are more likely to contribute to the company on weekends. If instead you have other hobbies or a family that takes up non-work hours you are more likely to drop your pen after forty hours.

Maybe they're selecting for intrinsic motivation. People who enjoy programming to the point they do it for fun, not just because it pays.

Free software work doesn't imply we work for free. We work on our projects, the stuff that we actually enjoy working on. Nobody is going to work on corporate products without adequate compensation.

> If you contribute to open source you are more likely to contribute to the company on weekends

I wonder if that assumption is bourne out in reality though?

I'd imagine if someone's OSS contributions are enough of a factor that it's worth hiring them, they're not going to drop it on a whim to work extra hours on the day job.

(Assuming you weed out open source contributions like "I made a todo list app in React but licenced it as MIT" or "I fixed a typo in the docs for NextJS". )

You might have numbers on that but after working in a place with a strict no more than 40 hour policy my view is that people overwork for many reasons. Being an open source enthusiast is not one of them.

I'm not sure that follows. I stopped making open source contributions when I switched from mature companies to startups.

Now all my "non-work" time is spent on startup work. And none of that is visible via GitHub.