Deposit Contracts for Quitting Smoking: How Betting on Yourself Works
A deposit contract is an agreement in which you pay in your own money before you quit and receive it back only if a test shows you stayed smoke-free. In trials, it helped the people who signed up, although most people offered one declined. This guide explains how it works, what the research found, and how to try one.
membrana.app · Last updated
What is a deposit contract?
A deposit contract is a commitment you make with money. You hand over a sum of your own before you quit, and the terms are fixed in advance: pass the tests and it comes back, fail and it does not.
It is not a reward. Nobody pays you to quit. The only money involved is yours, and the only way to lose it is to smoke. The deposit is not a fee and not a price.
Why does putting money down work?
People feel a loss more sharply than a gain of the same size, which economists call loss aversion. A deposit turns quitting from something you might gain into something you already own and could lose.
In a small trial with 25 people, all 13 who stood to lose money managed at least one smoke-free day, against 8 of the 12 who stood to gain it. Those who stood to gain were better at keeping it going once they had started. So a loss is a strong push to begin, and it is not a magic trick.
Romanowich P. & Lamb R. J. (2013). The effect of framing incentives as either losses or gains with contingency management for smoking cessation. Addictive Behaviors, 38(4), 2084-2088.doi.org/10.1016/j.addbeh.2013.01.007
It also settles the decision once. On a hard day you are not deciding whether to quit again. You are deciding whether one cigarette is worth the deposit, and tests on days you cannot predict keep that true every day.
What does the research show?
A Cochrane review pooled 39 trials with 18,303 people. People offered incentives were about one and a half times as likely to be smoke-free six months or more later (risk ratio 1.52, 95% confidence interval 1.33 to 1.74). The effect remained when trials that were still paying at follow-up were left out.
Notley C. et al. (2025). Incentives for smoking cessation. Cochrane Database of Systematic Reviews.doi.org/10.1002/14651858.CD004307.pub7
In a US trial with 2,538 people, 13.7% of those assigned to a deposit programme accepted it, against 90.0% of those assigned to a pure reward. Among those who did accept a deposit, 52.3% stayed smoke-free through six months, against 17.1% of those who accepted a reward.
Halpern S. D. et al. (2015). Randomized trial of four financial-incentive programs for smoking cessation. New England Journal of Medicine, 372(22), 2108-2117.doi.org/10.1056/NEJMoa1414293
Smokers were offered a savings account that returned their deposits only if a test at six months showed no nicotine. 11 percent took it up. Those offered it were 3 percentage points more likely to pass, and the effect persisted in surprise tests at twelve months.
Giné X., Karlan D. & Zinman J. (2010). Put your money where your butt is: a commitment contract for smoking cessation. American Economic Journal: Applied Economics, 2(4), 213-235.doi.org/10.1257/app.2.4.213
In a small internet-based study, nine people deposited amounts they chose themselves. While the contract ran, 47% of their breath samples met the smoke-free criterion, against 1% beforehand. The study did not measure long-term quitting.
Jarvis B. P. & Dallery J. (2017). Internet-based self-tailored deposit contracts to promote smoking reduction and abstinence. Journal of Applied Behavior Analysis, 50(2), 189-205.doi.org/10.1002/jaba.377
These studies tested deposits and incentives in general, not Membrana itself.
How does it compare with other ways to quit?
| Feature | Deposit contract with tests | Quit-smoking apps | Pledge sites without testing | Nicotine replacement |
|---|---|---|---|---|
| Main mechanism | Loss aversion. Your own money returns only if the tests are negative. | Tracking, reminders and encouragement. | A promise, sometimes with money, kept on your word. | Replaces the nicotine while you stop smoking. |
| Proof of not smoking | Saliva nicotine tests on random days. | None. You report it yourself. | None. You report it yourself. | Not part of the product. |
| Your own money at risk | Yes, the deposit. | No. | Sometimes. | No. |
| Medical treatment | No. | No. | No. | Yes, a licensed medicine. |
How to try a deposit contract for 30 days
- Take a face photo. It is how each test is matched to you.
- Choose a deposit from €25 to €2,000. Your challenge starts when you pay.
- Get at least ten saliva nicotine tests, and a few spare. You have 21 days to do the first.
- Do the first test when you are ready. Your 30 days begin that day.
- Do nine more on random days. Each time you have 24 hours.
- A person reviews the month. With no missed test, no positive test and no cheating, the deposit returns in full.
- Done
- 4 of 10
- Checks left
- 6
- Deposit
- €100
How much should you put down?
Choose an amount you would truly mind losing and can afford to lose. Too small and it will not hold you on a hard day. Too large and you may never start. If you are unsure, start small: €25 is enough to learn how the checks feel.
What can go wrong?
- Nicotine from any source.
Patches, gum and vaping all make the test positive. The test reads nicotine, not smoke.
- A missed test.
Each check gives you 24 hours. A missed check means you do not pass, and the deposit is not returned.
- Not starting in time.
You have 21 days to do the first test, then one final week after a notice. If you still have not started, the challenge counts as failed and the deposit is not returned.
Is a deposit contract right for you?
It suits people who have already decided to stop smoking or vaping and do not fully trust themselves to stick to it. It asks a lot: your own money, and no nicotine at all for 30 days. If you plan to quit with patches, gum or a vape, this is not the right tool.
Membrana is not a medical treatment or a diagnosis and does not replace advice from a doctor. If you are pregnant, have a health condition or take medication, talk to a doctor before you quit.
Frequently asked questions
- Do I get my deposit back?
- Yes, in full, when every test in your 30 days is negative and a person has reviewed the month.
- Can I use patches, gum or a vape?
- No. Any nicotine makes a test positive, whatever it comes from. No nicotine in any form during your challenge: no cigarettes, no vaping, no heated-tobacco sticks, no nicotine patches, gum, lozenges, sprays or pouches.
- How are the tests done?
- You do a saliva nicotine test yourself and film it with your phone. It takes about five minutes.
- Can I cancel?
- Yes, before your first check. If you paid for a plan, the plan fee is refunded in full. The deposit is not a fee: cancelling counts as not passing, so it is not returned.
- Is this a medical treatment?
- No. Membrana is not a medical treatment or a diagnosis.