Nash bargaining solution

Bargaining theory asks how two parties with different goals should agree on one option. The Nash bargaining solution chooses the option that maximizes the product of each party's gain over a fallback (the disagreement point). The Kalai-Smorodinsky solution instead gives each party the same fraction of the best gain they could possibly get.

Many surgical choices have this shape. A more aggressive resection improves tumor control but raises complication risk. Framing tumor control and safety as two parties lets a decision tool show the frontier of efficient plans and point to a principled compromise.

These solutions do not replace patient preference. They make the trade-off explicit so that the conversation is about values, not about hidden assumptions.