This article uses unique community-level data aggregated from censuses of associations to analyze growth and volatility in rural populations of grassroots associations. A qualitative comparative analysis (QCA) shows that the two main paths to growth were (1) centralization in polycephalous (multicentered) municipalities and (2) population growth in secular municipalities. High volatility occurs in (1) societies exposed to metropolitan sprawl and (2) traditional peripheral communities with high organizational density and little sociocultural change. Despite this volatility, associational life expanded in the sprawling areas that underwent extensive sociocultural change as well as in the peripheral areas where centralization took place. By contrast, more static peripheries experienced decline. The findings challenge romanticized images of stable, small-scale communities and nuance the negative view on metropolitan sprawl. (Contains 2 figures, 2 tables and 4 footnotes.)