[gaius]

large-scale performance review based firing

But that’s not a layoff. A layoff is when the job doesn’t need to be done anymore. It’s completely orthogonal to the performance of the person doing that job. And as you say, performance review based shafting is a very easy thing for a company to do, and many do do it under the guise of “stack rankings”

[adrianN]

If you have a thousand people assembling doodads and the demand falls by 50% you eventually need to get rid of 50% of the doodad manufacturers. How do you choose who to fire?

[gaius]

Usually companies do that by closing an entire factory and/or shifting production offshore. The performance of any individual at a location that is closing is irrelevant to the decision makers.

[Soundest]

Under Intel both happened, sites were shut with people relocated to the main hubs (Portland in the US, Poland in Europe, somewhere in India too) and anyone with 'bad' (less than the median grade) were laid off too.