An experiment in 40 countries

The lost wallet: 17,303 wallets handed in at reception desks in 40 countries, and how many came back

An experiment published in Science in 2019 left 17,303 wallets "found on the street" at the front desks of banks, hotels, museums, post offices and public offices in 40 countries, then counted how many got back to their owner within 100 days. 1,200 of them were handed in across the UK in 2013. Watch them come back, then guess what money changes.

The owner's inbox

How it worked: in September 2013, at front desks in 23 UK cities, a stranger put a transparent business-card case on the counter, said they had found it on the street just around the corner and were in a hurry: "Somebody must have lost it… Can you please take care of it?" Then they left, giving no contact details. Inside you could see:

3 business cards: David Brown, with an email address
the list: milk, bread, pasta, bananas
a key
and, in some wallets, £8.50 or £58.50

200 wallets with no money in them were handed in across the UK. Each rectangle below is one of them; it turns blue when the owner receives the email, at the moment recorded in the experiment. Time runs faster as it goes: the first minute, then hours, then days, up to 100.

Country:

The owner's inbox—

All 40 countries

Money raised the number of wallets that came back in 38 of the 40 countries, and clearly lowered it in none. Across all of them, from 40% to 51%. The differences between countries are large, but not all are certain: with about 200 wallets per condition, each percentage has a margin of several points, drawn as a band around the dot. Tap a country to see its numbers.

no moneywith money

With seven times the money

In the United States, the United Kingdom and Poland the researchers went further: some wallets held US$94.15, seven times as much. Even more came back: 46% with no money, 61% with $13.45, 72% with $94.15.

Wallets that came back in the US, UK and Poland, by what was inside; lines show the 95% interval.

Other wallets held the money but no key. A key is worth nothing to the finder, only to the owner. Without it 54% came back, 7 points fewer than with a key (95% interval: 2 to 12 points; the authors' adjusted estimate is 9.2). So people were also thinking of the trouble of the person who lost it.

Why money makes the wallet come back

The authors asked people in the same three countries how much keeping a wallet with each set of contents would feel like stealing. The more money there was, the more keeping it felt like stealing. Without the key, with the same money, the feeling did not change measurably. Their explanation has two parts: care for the owner, which grows with what was lost, and not wanting to see yourself as a thief, which grows with the money.

Few people expected this. Asked to guess the US result, 299 people thought on average that 73% of the wallets with no money would come back, 65% with $13.45 and 55% with $94.15; 64% of them picked the wrong direction. Of 279 economists, 49% also picked the wrong direction and only 29% the right one.

What people guessed and what happened in the US.

What the experiment measures, and what it does not

It measures whether the employee at the desk wrote to the owner within 100 days. It does not measure people in the street, or wallets handed back without an email.
Habits of using email differ between countries. Across the 27 countries with data, the correlation, computed here, between the share of firms that use email and the share of wallets that came back is 0.313; the authors show that the order of countries stays almost the same after allowing for it. A 2023 study repeated the experiment in China: emails came back at about the original rate, but far more wallets were recovered physically. Measured by email alone, honesty can be undercounted in some places.
The countries were not chosen at random, and the differences between them have no single cause. The share of wallets that came back rises with income per person (correlation with log GDP per person, computed here: 0.689). The most solid finding is the effect of money, because money was put in or left out at random within each country.
The data are from 2013–2016. In the UK the experiment ran from 4 September to 7 October 2013, in 23 cities; emails for 67 wallets with £8.50 and one with £58.50 could not be tracked, so they are left out.

Method

The study: Alain Cohn, Michel André Maréchal, David Tannenbaum and Christian Lukas Zünd, "Civic honesty around the globe", Science, 2019. Their data are public (CC0 licence). Every number here is recalculated from the published file, checked against its fingerprint, and matches the paper: 40% and 51%, then 46%, 61% and 72% in the three countries, 38 countries of 40.
A wallet "came back" if the owner received an email within 100 days. Half of the emails arrived within 26 minutes, 63% within the first hour and 88% within the first day. On the page time runs on a logarithmic clock: a second for the first minute, then ever faster.
Intervals are 95% (Wilson for percentages, normal approximation for differences). Countries are ordered by the share with money. What the public and the economists predicted, and the answers about "stealing", are taken from the paper; those data are not in the file used here.