Are residents of ethnically diverse communities less likely to encounter
acts of cooperation and kindness from strangers? Although a vast
literature has arisen examining the relationship between ethnic
diversity and popular attitudes such as social trust, we know little
about how prosocial behaviors vary across neighborhoods. This
study presents evidence from a ‘lost letter’ experiment conducted
across 77 neighborhoods in 13 German cities. We experimentally
vary the ethnic identity of letter senders and recipients, and also
carefully select our experimental field sites to create ‘matched
sets’ of neighborhoods that differ only with respect to the
percentage of foreign residents. We find no difference in return
rates across our ethnicity treatments, and no overall relationship
between return rates and neighborhood diversity. However,
comparing across ‘matched sets,’ we do detect significantly lower
return rates in areas featuring higher unemployment. Taken
together, our findings support the view that it is not diversity per
se, but rather associated socioeconomic deprivation, which is
most detrimental to cooperative neighborhood interactions.