[tgma]

If you watch the Peter Norvig link you shared on YouTube he actually interprets the phenomenon quite clearly: the statistic reported is only true for the subsample of people who get hired and absolutely not true for the general candidate population.

(Personally I would add that human measures of “job performance” can also be quite subjective.)

[nitwit005]

You're imagining I didn't listen to an extremely short clip of a talk that I linked to?

Yes, implicitly Google can only measure the job performance of people they actually hire.

[tgma]

I did not mean to imply you in particular did not watch it. The way this observation often gets quoted is extremely misleading (often intentionally so, as the first piece without the second is much more sensationalistic) and needs an explicit clarification, as Norvig did immediately after reporting the curious observation.