Economics Webinar - A Structural Life Course Model of Dynamic Role Selection on an open Q&A Platform for Pregnancy and Childbirth

This study expands the scope of two-sided market literature by exploring indirect  network effects that arise from users’ transitions from one side of the networks to the other as  opposed to arising from the interaction between distinct user groups. Utilizing unstructured text  data from an open Q&A platform focused on pregnancy and childbirth, we employ topic modeling to identify latent themes within a collection of posts. We further investigate active 
learning processes among users by analyzing the similarity between previous answer sentences and subsequent answer posts using sentence cosine similarity measures. On this platform, users seamlessly shift roles as question askers and answer givers, navigating a sequence of life course events throughout pregnancy. We examine the dynamics of distinct topics discussed on the platform and report stylized data patterns that suggest the platform internalizes individual users’ knowledge acquired on the platform by deploying them as answer givers. We develop a structural model of two-sided markets where users endogenously choose to participate as answerers based on their prior learning experiences as askers. Counterfactual experiments shed light on users’ dynamic role selections that promote the internalization of knowledge shared on open Q&A platforms and uncover the platforms’ potential for growth through enhanced user interaction.