Commitment contracts: how they work, what the research says and how to write one

What a commitment contract is

Economists call it a commitment device: something you set up today so that your future self, tired and tempted, sticks to the plan you made with a clear head. A commitment contract writes that down. It names the rule, the time frame, who checks, and what happens if you break it.

Researchers distinguish hard and soft commitments. A hard commitment has a real consequence, such as money you forfeit. A soft one is mostly psychological, such as a promise to a friend or a public goal. Both can help. Hard ones bite harder, and they need more care to set up fairly.

What the research found

The best-known trial tested a product called CARES in the Philippines. Smokers could open a savings account, deposit money for six months and then take a urine test for nicotine. If they passed, they got their money back. If they failed, it went to charity.

• Only 11 percent of smokers offered the contract took it up.
• Smokers randomly offered it were 3 percentage points more likely to pass the test at six months than the control group.
• The effect held in surprise tests at twelve months, after the contract had ended.

A larger US trial in the New England Journal of Medicine compared rewards with deposits for 2,538 smokers: CVS Caremark employees and their relatives and friends. The deposit programs asked for $150 of their own money, refunded on success, plus $650 in rewards for those who quit. The reward programs offered about $800 with no deposit.

• 90 percent accepted the reward programs, but only 13.7 percent accepted the deposit programs.
• Every incentive program beat usual care: sustained abstinence at six months was 9.4 to 16.0 percent, against 6.0 percent.
• Overall, rewards did better (15.7 vs 10.2 percent), because so few people signed up for deposits.
• But among people who would accept either, the deposit programs produced 13.2 percentage points more abstinence at six months.

Put together: putting your own money on the line works for the people who choose it, and most people don't choose it. That is fine. A commitment contract is a tool for people who want one, not a rule for everyone.

Why losing money motivates more than winning it

Tversky and Kahneman's prospect theory describes loss aversion: a loss feels bigger than a gain of the same size. A 2024 meta-analysis of 607 estimates from 150 articles put the average loss aversion coefficient at about 1.96, so a loss weighs roughly twice as much as an equal gain.

A commitment contract uses that asymmetry on purpose. In the moment of temptation, the short-term reward is vivid and the long-term cost is vague. The contract adds a near, concrete cost that you would genuinely rather avoid.

How to write a commitment contract that works

1. Write one clear rule"No gambling sites or apps", "no porn", "social apps 30 minutes a day at most". Not "less" or "better". If two people could disagree about whether you broke it, rewrite it.
2. Set a fixed end date30, 60 or 90 days is long enough to change routines and short enough to keep in view. You can sign a new one afterwards.
3. Decide how it is checkedYour word alone is the weakest form. Better: a test, device data, a blocker that reports when it is switched off, or a person who can see the evidence.
4. Choose a refereeSomeone who will judge honestly, neither out to catch you nor willing to wave everything through. Agree on how a dispute is settled before it happens.
5. Pick an amount that matters but won't hurtEnough that you would rather keep it, never money you need for rent, bills or debt. If losing it would be a crisis, the amount is too high.
6. Decide what counts as breaking itIs a single slip a breach? What about a device left unprotected? Write it down, along with what you will do after a slip, because the contract should end a slide, not start one.
7. Sign it and make it visibleDate it, sign it, give a copy to your referee. Our free template walks you through every line.

Risks, and who should not use one

• If money is tight, don't use money. A commitment contract should never be able to put you in financial trouble. Use a soft commitment instead: a promise to a person you respect, or an honor-based pledge without money.
• If you have a gambling problem, start with help. Anything that ties money to an uncertain outcome can feel too close to gambling. If gambling has cost you money you can't spare, a helpline or self-exclusion comes first, and a no-money commitment is the safer choice.
• Vague rules cause fights. If the rule is fuzzy, you will either argue with your referee or quietly let yourself off.
• Too ambitious backfires. A rule you are likely to break in week one costs you money and confidence. Start with what you can keep.
• It is a tool, not treatment. If the habit comes with depression, anxiety or serious debt, see a professional as well.

Clearing's pledge: one kind of commitment contract

Clearing's optional pledge is a commitment contract built into a blocker. It differs from the classic deposit in two ways. No money is held up front: your card is saved, not charged. And the check isn't your word alone: protection is verified on your devices, and switching it off counts.