> After losing a key member of a team, perhaps the survivors find they have other priorities in life than trying to file for lots of patents. This seems like a rather obvious confounding factor.

Exactly, seems pretty disingenuous to measure grieving people's productivity and compare based on whether they're grieving the death of a native or immigrant.

If I lost my cofounder (who isn't a migrant) I would be devastated and probably wouldn't produce much of anything for a year or two.

If they were from another country and I didn't even have any of my cofounder's family around, just a big gaping hole where they used to be... I'd probably quit and go find a job somewhere else so I could stop thinking about it.

Getting a patent application in would be the very last thing on my mind.

Sure, but their being foreign changing behavior a lot more? It's possible but its a better finding than Freud ever had.