If I receive a lost wallet once a month, I may trying contacting the owner. If I am busy with tons of customers and pick up multiple lost wallets every week, I definitely would not spend hours sending emails to all owners - it is not my job. I will instead hand it over to the police officer or just keep the wallets at LOST & FOUND, waiting for owners. This way of thinking actually supports the results why people tend to return the wallets with more money - because they believe it is more important and necessary to contact the owners rather than passive waiting. It is probably difficult for the westerners to imagine the real life of living in a country with more than one billion people, otherwise they would not test the "honesty" using such a bad experimental design.