While ethnic diversity has been shown to produce numerous negative effects on the economic performance due to disagreement on the production of the public good, nepotism in making employment decisions, increased corruption and rent‐seeking behaviour, its positive effects appear to have received much less attention. We hypothesise and test several explanations why higher levels of ethnic diversity may be associated with better socio‐economic outcomes. We find that productive efficiency will be higher in the societies where ethnicities can benefit from the complementarity of skills. Incentives to engage in an ethnic conflict will be lower and the extent of political stability higher in those countries where the opportunity costs of ethnic conflict are more substantial. We also find some evidence in support of the political aspirations hypothesis that attributes the negative effects of ethnic diversity to the strife by ethnic groups for more political influence.