Treating a divisible-surplus situation as fixed-pie produces conflict that the underlying structure does not require.
Von Neumann and Morgenstern's framing, and the negotiation consequence is direct: parties who assume a fixed pie stop searching for trades, so the surplus that would have existed never gets found.
In practice
- A buyer and a seller who each assume price is the only variable never find that one needs delivery in March and the other has spare capacity in February.
- Two departments arguing over a budget line never discover that one values timing and the other values total, which is a trade both would take.