This study examines the eﬀect of a speciﬁc information nudge - information on how much people in diﬀerent income groups donate - on one's donation decisions through a survey experiment. I investigate the nudge eﬀects in various dimensions: subjects' demographic characteristics, donation amounts in diﬀerent income deciles, religious or non-religious donations, etc. I found three main results. First, the nudges work diﬀerently, depending on gender. Second, the nudges make donation amounts converge through social comparison. If people ﬁnd out that they donate more than other people, their donation amounts tend to decrease, and vice versa. Third, religious and non-religious donations are substitutes.