Panek, Elliot, et al. "The effects of group size and time on the formation of online communities: Evidence from Reddit." Social Media+ Society 4.4 (2018): 2056305118815908.

This study investigates the effects of group size and time on participation dispersion and member turnover in online communities, using Reddit as a case study. Analysis of 30 groups over 6 years shows that larger groups tend to have a concentration of participation among fewer members and lower turnover rates, while over time, participation disperses more widely, and turnover increases due to both maturation and cohort effects. The findings suggest that as online groups grow and age, their community dynamics shift, becoming less community-like in distinct ways.