Write a formal commitment contract with a referee and stakes

Formalize your goal with a clear metric, a deadline, stakes you’ll lose if you fail, and a referee who enforces it.

Why it works

A formal contract exploits loss aversion and social accountability simultaneously: the prospect of losing money or reputation makes the cost of failure immediate and concrete, while the referee prevents quiet renegotiation. The specificity of a written contract also reduces the ambiguity that allows people to rationalize failure as "close enough."

How to do it

1. Define your goal in precise, measurable terms (not "exercise more" but "run 3×/week for 8 weeks").
2. Choose a stake that is genuinely aversive — a financial amount, a public commitment, or an anti-charity donation.
3. Designate a referee who is not your cheerleader: someone willing to call a miss a miss.
4. Put the contract in writing, even if only in an email to the referee.

Evidence

Commitment contracts have RCT support in savings (Ashraf et al., SEED accounts) and in smoking cessation (Gine, Karlan & Zinman). Meta-analyses of commitment devices generally find positive but heterogeneous effects across contexts. (rct)

Effects are strongest for people who self-select into commitment contracts — they already want to change. When commitments are offered but not chosen, effects are smaller. Some financial commitment devices for health (e.g., stickK) show mixed results in natural field use.

Sources

• Gine, Karlan & Zinman (2010), "Put your money where your butt is: A commitment contract for smoking cessation", American Economic Journal: Applied Economics
• Ashraf, Karlan & Yin (2006), "Tying Odysseus to the mast: Evidence from a commitment savings product in the Philippines", Quarterly Journal of Economics

Common mistake

Choosing a stake that sounds meaningful but isn’t actually aversive enough to change behavior — the number needs to sting, not be performative.