Farmer–herder conflicts across West Africa are conventionally attributed to competition over land and water. Yet, identity – ethnic difference and outsider status – features prominently in qualitative accounts and in the peacebuilding programming that targets these conflicts. Because occupation and identity overlap closely in the field, observational data cannot easily distinguish these accounts. We test this experimentally, using a pre-registered vignette experiment among 1,765 farming households located at the Sierra Leone–Guinea border. We randomize the counterpart’s identity while holding their occupation and the economic terms of an everyday exchange fixed. We find clear evidence of group-based discrimination: over a third of respondents always buy from their economic ingroup, even when doing so would mean paying more in the purchase scenario. However, this discrimination is not widened or heightened by the ethnic or national identity of the counterpart. Neither nationality nor tribe cues move purchase behavior or stated social acceptance: estimates are close to zero, and equivalence tests rule out effects at the lower bound of those documented in the intergroup-bias literature. The results suggest that the economic identity divide between farmers and herders is more salient than ethnic or national identity, with implications for where social-cohesion programming is best directed.