Eliciting Legal Status Through Social Media Surveys Among Immigrants—Evidence from a List Experiment, Direct Question and Stepwise Exclusion

Estimating the size of the undocumented migrant population remains a critical challenge for researchers and policymakers. This study assesses the viability of using social media platforms, specifically Facebook and Instagram, to recruit a survey sample of migrants and elicit their status. The research focuses on Mexican and Venezuelan immigrants in Texas, Florida, Illinois, and California. Three methods for eliciting legal status are tested: direct questions, indirect sequential questions (stepwise exclusion), and a list experiment. The study (N = 2,027) finds that while social media recruitment is cost-effective and rapid, it faces challenges such as selection bias, misclassification, and platform-imposed restrictions. The list experiment suggests the presence of response bias in traditional surveys to sensitive legal status questions. Estimates of the share of undocumented migrants deviate considerably from available reference estimates. We argue that social media surveys are best applied in preparation for traditional surveys rather than in their place.