Ethnic diversity has been widely associated with lower levels of social harmony. The main reason for this
is the proven existence of ethnic biases, which have been shown to impact romantic preferences, neighborhood choices, job recruitments, electoral votes, and political stability, among others. Oftentimes, however, the ethnic dimension cannot be easily disentangled from other dimensions of identity, such as class or nationality. Hence, the independent effect of ethnic diversity remains to be fully understood. This project aims to fill in this gap: by leveraging Singapore’s unique demographic composition, it aims to pin down the independent effect of ethnic, national and socioeconomic identities on social harmony. To be precise, the goal is to measure the extent to which they impact (if at all) pro-social, altruistic behavior. To do so, we conduct a field experiment, using the “misplaced envelope technique”. This consists of sending envelopes with valuables inside (in our case, a voucher) to the wrong addressee. The actual recipient, upon realizing that (s)he is not the intended recipient, can choose to keep the voucher or return it. By randomizing the ethnicity, nationality and socio-economic status of our actual and intended recipients, we can assess which dimensions trigger altruistic behavior (i.e., returning the voucher to the correct addressee) over others. Our study bears important contributions. Theoretically, uncovering how these different affiliations affect altruism will help us understand broader questions about the process through which national integration and social cohesion can be cultivated in a multiethnic context. Methodologically, to the best of our knowledge, our study will be the first to analyze this issue by using observed behavior, as opposed to survey data, hence overcoming social desirability biases that arise in surveys. In terms of policy, our findings should shed light on how social integration and cooperation across groups can be strengthened.