Full wallets more likely to be returned

The study involved more than 17,300 "lost" wallets in 355 cities between 2013 and 2016. Photo / 123RF

Lost wallets are more likely to be returned when they contain a larger amount of money, a study suggests.

Researchers who left 17,000 wallets around the world said that in 38 out of 40 countries studied, levels of honesty increased as the value of the contents rose.

The study, published in the journal Science, involved more than 17,300 "lost" wallets in 355 cities between 2013 and 2016. Each was a transparent card holder and contained a key, a grocery list, three business cards and the contact details for the owner, who was made to look like a local resident.

They contained no money, or the local equivalent of US$13.45 ($20.40).

Research assistants travelled the world leaving the wallets in hotels, banks and post offices before recording whether the finder contacted the owner to return it within the next 100 days. Globally, around 40 per cent of the wallets containing no money were returned, compared with 51 per cent of those that contained cash, the study found.

"In virtually all countries citizens were more likely to return wallets that contained more money," the researchers said. Mexico and Peru were the only countries where the trend was not seen. Switzerland was the most honest.

The team also ran a study in Britain, the United States and Poland, adding a wallet containing the equivalent of US$94.15. Return rates were 72 per cent for the largest sum, 61 per cent for the smaller amount and 46 per cent for wallets with no money.

Researchers said "theft aversion" — the fear of viewing oneself as a thief — could explain the findings.