About
Ask a yes or no question, and let Jev or a fair coin make the call. The idea comes from a real experiment.
How it works
Ask Jev
Jev is the first System One model from TypeSafe. It does not write text or chat. It answers typed questions with probabilities. Your question goes to Jev with four questions about it, all in one request:
- Is it a decision you can settle with yes or no?
- Should you do it? The probability of yes is Jev's answer: yes at 50% or more, no below.
- How big a decision is it: trivial, minor, notable or major?
- Does it hint at a crisis that nobody should decide with a coin or a computer?
Add details with the slider button in the question box and Jev weighs them too. When Jev is within ten points of 50/50, it says it is on the fence.
Flip a coin
A fair flip made in your browser with its cryptographic random number generator. Heads means yes, make the change. Tails means no, keep things as they are. As on the website in the study, you can flip once or go for best two out of three. Tick “Also flip a coin” to ask Jev and flip at the same time and see whether they agree.
One trick worth knowing: notice how you feel the moment the answer appears. A flash of relief or disappointment often tells you what you wanted all along.
The coin toss study
Steven D. Levitt (2016). “Heads or Tails: The Impact of a Coin Toss on Major Life Decisions and Subsequent Happiness.” NBER Working Paper 22487.
Do people make good choices when the stakes are high? Economists had little to say, because nobody can randomly assign people to quit their jobs or leave their partners. Steven Levitt, the economist behind Freakonomics, found a way around that: he asked people who were truly stuck on a decision to let a coin make it.
How it worked
The website FreakonomicsExperiments.com opened on January 23, 2013. Visitors picked a decision from a menu, or wrote their own, and answered a short survey about it, including how happy they were. Then a virtual coin was flipped. In most cases, heads meant make the change and tails meant keep things as they are for at least two months. About 56% chose best two out of three over a single flip. Two and six months later, people were asked what they did and how happy they were. About 30% also named a friend or relative who was surveyed to check their answers.
The most popular questions
| Question | Coin tosses | Counted as |
|---|---|---|
| Should I quit my job? | 2,186 | Important |
| Should I break up? | 1,686 | Important |
| Should I splurge? | 1,491 | Less important |
| Should I go back to school? | 1,203 | Important |
| Should I go on a diet? | 1,134 | Less important |
| Should I break my bad habit? | 984 | Less important |
| Should I start my own business? | 893 | Important |
| Should I get a tattoo? | 876 | Less important |
| Should I move? | 762 | Important |
| Should I try online dating? | 699 | Less important |
From Table 1 of the paper. Over 3,000 people also wrote questions of their own.
Did people listen to a coin?
More than you might think. Two months after the toss, about 63% of people had done what the coin said, well above the 50% you would expect if the coin made no difference. People who got heads were about 25 percentage points more likely to make the change than people who got tails. The coin mattered most for small decisions, where over 67% followed it, but still moved big ones such as quitting a job or breaking up, where about 56% did.
Were they happier?
Because the coin was random, the people it pushed toward a change were otherwise just like the people it did not. That makes it possible to measure what making the change itself did to their happiness. For important decisions, making the change made people happier: the effect was small and uncertain at two months but large at six months, with quitting a job and breaking up standing out. For less important decisions, such as a diet or a splurge, changing made little difference either way.
“The results of this paper suggest that people may be excessively cautious when facing life-changing choices.”
The fine print
Happiness was self reported, not everyone answered the follow up surveys, and people who visit a coin tossing website are not a random slice of the population. Levitt calls the results “merely suggestive.” The study is about people who were truly on the fence; it does not say that every change is a good one.
How this site is different
Let Jev Decide borrows the study's coin: heads means yes, and you can flip once or go for best two out of three. It does not survey you or follow up. It also adds a second decider, Jev. Keep in mind that only the coin is random: Jev's answer depends on what you tell it, so it cannot do what the coin did for the study, which was to split people into two groups that were alike in every other way.
Cite the study
Levitt, Steven D. 2016. “Heads or Tails: The Impact of a Coin Toss on Major Life Decisions and Subsequent Happiness.” NBER Working Paper 22487. National Bureau of Economic Research. https://www.nber.org/papers/w22487
Published as: Levitt, Steven D. 2021. “Heads or Tails: The Impact of a Coin Toss on Major Life Decisions and Subsequent Happiness.” The Review of Economic Studies 88 (1): 378-405. https://doi.org/10.1093/restud/rdaa016
Privacy
When you flip a coin, nothing leaves your browser. When you ask Jev, your question and any details go to the relay at letjevdecide.xera.ac and on to TypeSafe for an answer. The relay keeps no copy of them. Your history is saved only in this browser, and you can clear it at any time. There are no cookies, no analytics and no trackers. The page loads its font from Google Fonts.
Getting help
Jev and the coin are for fun and for getting unstuck; they are not professional advice. If a question hints at danger to you or someone else, neither will decide it. If you are thinking about suicide or about hurting yourself or someone else, please reach out now. In the US, call or text 988 or chat at 988lifeline.org. In an emergency, call 911. Outside the US, find a line near you at findahelpline.com.