McKenna, Liz2026-08-25McKenna, Elizabeth. "Many Show Up, Few Return: Leadership and Retention in Civic Associations." HKS Faculty Research Working Paper Series RWP26-009, August 2026.https://p2p8-sa-zuvru-a9vusux.re-cotta.com/handle/1/42752914Mass protest has reached record levels, yet the movements producing it have rarely been weaker. Why does so much participation leave so little behind? Most explanations center on recruitment, while retention has received far less attention. Drawing on a year of participation records from 20 organizations across 11 states, paired with prospective interviews and fieldwork, I observe 91,648 attendances by 38,740 people who took civic action beyond voting. I find that 71 percent of these participants act once and do not return within the observation window. Among those whose first participation was a mass mobilization, attrition approaches 90 percent. Across all groups, however, similarly sized events resulted in very different retention rates. I call the capacity behind these differences catchment and trace it to organizational practice. A first event where most of those present are established members raises the probability of return within 90 days by 12.8 percentage points, net of event size and robust to organization-clustered inference. The pattern holds across constituencies and regions, and in 13 years of records from one organization. The strongest organizational correlate of catchment is the share of members embedded in teams.Working Paper