If children contribute to the household by using their time to collect natural resources from common property sources—such as collecting firewood, fetching water, collecting fodder, grazing animals—then local depletion of these resources could potentially increase the demand for children. This feedback could create a dynamically unstable ‘vicious circle’ between population growth and resource depletion. We empirically examine several elements of such a ‘vicious circle’ hypothesis using data from Pakistan with unusually rich detail on both child time use and firewood collection activities. We find that collection activities do absorb a substantial part of household resources; that children's tasks are relatively devoted to collection activities; that child time is a significant, but not a dominant, portion of collection activities; and the presence of older children in the household reduces the time that women devote to household tasks. Exploratory multivariate regressions show a partial correlation between indicators of firewood scarcity and fertility—a relationship that varies across regions of Pakistan.