Bilinguals in the Lab: (Why) Does Randomising Language Affect Cooperation?
Uganda is typical of many African countries. Its 43 million people speak a combined total of 43 living languages. Economists have recently become interested in the multilingual nature of daily life, asking whether the language spoken influences decisions. A few studies use bilingual subjects and find significant differences in revealed preferences when the language of an experiment is randomised. However, it isn't clear whether publication bias has affected this picture. Nor has the mechanism leading to differences been fully identified. This paper asks two main questions. First, using a preregistered design and analysis, are language effects replicable? We follow Clist and Verschoor (2017) by conducting a public goods game in Uganda, randomising between Lugishu and Luganda. Second, why does language affect the choices people make? The underlying mechanism could be a different social norm, a different expectation of others' behaviour, or because people have internalised different preferences. We answer these two questions, and present three main findings. First, we replicate the previous finding in a new urban setting. Subjects in the national language contribute 29% more than in the local language. This effect size is virtually identical to previous work. Second, we can rule out both norms and expectations as mechanisms. While ethnographic research predicts less cooperative norms in Lugishu, elicited norms are almost identical in the two languages. Expectations are slightly different, but do not explain contribution behaviour. Subjects wrongly expect greater cooperation when they play the game in the tribal language. This leaves internalised preferences as the mechanism. In Lugishu people do not contribute less because they expect others to give less (conditional cooperation) nor because of general social norms, but rather because they prefer to give less. Third, we show that there is substantial heterogeneity in how sensitive subjects are to norms and expectations. On average, subjects are less likely to chose options they believe will be popular, and less likely to follow normative behaviour. This holds for language level norms/expectations as well as a subject's own opinions. Our results show that people's revealed preferences are meaningfully influenced by the language in which they interact. Using a language which has historically been associated with low levels of cooperation lowers the extent to which they benefit from cooperative opportunities. We show that Gishus are characterised by unconditional cooperation in the national language, and unconditional non cooperation in their own. This has interesting implications for the importance of the language spoken in affecting revealed preference.