Seems hard to do a credible study on that. You'd need hiring managers to answer "how many more bootcampers would you have hired in a counterfactual world without AI", which seems very hard and subjective.

Intuitively you'd expect AI to be a big win for bootcampers. Their productivity is typically low because they're constantly hitting roadblocks and getting stuck, even on simple tasks. Unsticking them is an AI strong suit so they should be able to plough through tasks much more effectively despite still asking for the same low starting salaries.

Problem is, AI also benefits the more experienced types, even if less. And if you can pick between a desperate senior or a bootcamper, and the price gap isn't that big, why would you go for the bootcamper? The senior will still be much easier to work with even if they both would have access to top of the line models.

So it's got to be the layoffs (ending of ZIRP and COVID stimulus).