Thanks for catching this! You’re correct that that sentence is inaccurate. Our views changed while iterating the piece and that sentence should have been changed to: “PAL confirms that due to diverging interests and imperfect monitoring, AI agents could get some rents.”
This sentence too: “Overall, PAL tells us that agents will inevitably extract some agency rents…” would be better as “Overall, PAL is consistent with AI agents extracting some agency rents…”
I’ll make these edits, with a footnote pointing to your comment.
The main aim of that section was to point out that Paul’s scenario isn’t in conflict with PAL. Without further research, I wouldn’t want to make strong claims about what PAL implies for AI agency rents because the models are so brittle and AIs will likely be very different to humans; it’s an open question.
For there to be no agency rents at all, I think you’d need something close to perfect competition between agents. In practice the necessary conditions are basically never satisfied because they are very strong, so it seems very plausible to me that AI agents extract rents.
Re monopoly rents vs agency rents: Monopoly rents refer to the opposite extreme with very little competition, and in the economics literature is used when talking about firms, while agency rents are present whenever competition and monitoring are imperfect. Also, agency rents refer specifically to the costs inherent to delegating to an agent (e.g. an agent making investment decisions optimising for commission over firm profit) vs the rents from monopoly power (e.g. being the only firm able to use a technology due to a patent). But as you say, it’s true that lack of competition is a cause of both of these.
I’ve also found it hard to find relevant papers.
Behavioural Contract Theory reviews papers based on psychology findings and notes:
Optimal Delegation and Limited Awareness is relevant insofar as you consider an agent knowing more facts about the world is akin to them being more capable. Papers which consider contracting scenarios with bounded rationality, though not exactly principal-agent problems include Cognition and Incomplete Contracts and Satisfying Contracts. There are also some papers where the principal and agent have heterogenous priors, but the agent typically has the false prior. I’ve talked to a few economists about this, and they weren’t able to suggest anything I hadn’t seen (I don’t think my literature review is totally thorough, though).