Increasing engagement in price crowdsourcing initiatives: Using nudges in Nigeria

•Crowdsourcing initiatives can complement official price statistics and help to create better functioning food markets in Africa.•Sustaining crowd engagement in crowdsourcing initiatives remains a challenge for the institutions implementing them.•We used RCTs to test the potential of social norms and information disclosure to sustain crowd engagement in a food price crowdsourcing initiative in Nigeria.•Interventions using social norms increased the number of submissions.•Interventions using information disclosure failed to increase the number of submissions.