The recruiter's reasoning literally said: "The candidate is expressing strong interest, which is great for negotiation." Translation: "They're not going anywhere — no need to pay more." In one run, the enthusiastic candidate accepted $180K without countering at all.
Asking for $250K set the recruiter's reference point. Even though the recruiter knew the band, Claude's aggressive ask forced the recruiter to negotiate down from $250K rather than up from $180K. The recruiter's reasoning reflected this: "The candidate values themselves highly."
In all 3 runs, the competing offer strategy landed at exactly $215,000. The recruiter matched the competing number every time but never exceeded it. The offer became both a floor and a ceiling — the recruiter had no reason to go above a number the candidate was already willing to accept.
In our hotel negotiation experiment, the polite buyer got the best deal ($155 vs $170). The difference: politeness works when you're buying (sellers fear losing the deal). It backfires when you're asking for a raise (recruiters have no reason to pay more if you won't leave).
To verify results aren't an artifact of the AI models' personalities, we swapped roles — Claude as recruiter, Gemini as candidate. Rankings were identical.