Be a Good Samaritan to a Good Samaritan: Field evidence of other-regarding preferences in China

•A large-scale lost letter experiment was conducted in Beijing, capital city of China.•The experiment aimed to test if the altruistic attribute of the letter recipient would induce more letters to be returned.•The treatment letters were addressed to a nationally renowned charitable organization in China.•The control letters were intended to an invented individual.•A total of 832 ready-to-be-posted letters were distributed in 208 communities across eight districts in the city.•The return rate of the treatment letters (17%) was nearly twice as high as that of the control letters (9%).

We conducted a large-scale lost letter experiment in Beijing, a megacity with > 21 million residents, to test if the observed altruistic attribute of the letter recipient would induce more passersby to return the lost letters. The treatment letters were addressed to a nationally renowned charitable organization in China, while the control letters were intended to an invented individual. A total of 832 ready-to-be-posted letters were distributed in 208 communities across eight districts in the city. The overall return rate was 13%. Yet, the return rate of the treatment letters (17%) was nearly twice as high as that of the control letters (9%). The finding adds large-scale field experiment evidence in support of the other-regarding preferences theory. In addition, we also found that the lost letters were more likely to be returned if they were dropped in communities with a relatively higher income or a postal box located closer.