“Whatever the obvious answer is, test the opposite before conceding.”

# The Classic Solution—Then Challenge It **Standard answer:** One person cuts, the other chooses. This incentivizes fair division since the cutter wants equal halves or risks getting the smaller piece. **But testing the opposite:** What if we *prevented* choice? Have one person cut while blindfolded, then assign pieces randomly. This removes strategic advantage entirely—neither can game the system through cutting or selecting. **However**, the blindfold method risks genuine unfairness. The original "divide and choose" is actually superior: it's self-enforcing and requires no trust in the other party's fairness, only in rational self-interest. **Conclusion:** The obvious answer proves best because it aligns incentives perfectly.

“Let someone else spring the trap. Take what they were reaching for.”

# The Fair Division Method Use the classic "divide and choose" approach: **One person cuts the cake into two pieces** they believe are equal. This person has strong incentive to cut fairly—if they cut unevenly, the other person gets first pick of the larger piece. **The second person then chooses which piece they prefer.** This method works because: - The cutter's self-interest ensures fairness (they want both pieces equally desirable) - The chooser's distrust is satisfied (they get the piece they prefer) - No measurement or trust in a third party is needed Both parties find it fair by their own judgment.