Recruiting experimental subjects using WhatsApp

The aim of many experiments is to estimate the effect different interventions on subjects’ decision making. However, obtaining large samples and internal validity challenging. This paper presents an alternative device at almost no cost that can easily provide a very number participants (700 in 1 hour). We asked 14 students invite their WhatsApp contacts participate online experiment. created total 80 diffusion groups with 25 each. Using as clusters, we ran cluster randomization procedure order assign subjects framing experiment (treatment + control). obtained same level attrition, duplicates uninvited across treatment control groups. Moreover, yielded consistent results line literature.