Roles and Effects of Authenticity and Homophily in Influencer Marketing
(A2026-134064)

AUTHORS

Namita Goel, Pennsylvania State University; ARVIND RANGASWAMY, PennState Smeal College of Business; J. Andrew Petersen, Pennsylvania State University

ABSTRACT

We assess the extent to which the volume and speed of followers’ engagement with an influencer’s post are influenced by: (1) the authenticity (to both the influencer and to the brand) of sponsored posts, and (2) the homophily of an influencer’s network. Using Instagram data from Alo Yoga and Hello Fresh and doubly robust random forest causal estimation, we find that authenticity to brand drives volume and speed of engagement more than influencer self-authenticity. Greater follower homophily decreases both engagement volume and speed. Contrary to conventional wisdom, higher authenticity is not always better for driving engagement. We develop scalable text-based metrics using TF-IDF cosine similarity for authenticity and network density for homophily, overcoming limitations of survey-based measures. Keywords: Influencer marketing; Authenticity; Homophily, Casual Forest Track: Digital and Social Media Marketing