ZIRP alone isn’t even the full financial story - there was a time bomb tax change from a 2017 bill that impacted R&D (most software work) and that took effect in 2023.
But it’s fairly visible that big companies (eg Meta) that are spending a lot on AI are actually changing spending on headcount and hiring to maintain margins. It’s not the efficiency of the workers, it’s the maintenance of margins with big new spending.
The R&D tax credit change actually took effect in 2022, and one of the few good things Trump's BBB did was reverse it
The layoffs are happening all over, not just in USA. Atlassian has cut jobs. Spotify. Wisetech. Xero. It's happening all over. This is not a USA tax policy problem.
My first and only layoff was effective 1h before that law went into effect. 1,000s of us were shunted off b/c an entire research arm was canned due to the changing cost of research s/w teams.
I'm poorer but happier now b/c of it. That job was nuts.