This conclusion presents some closing thoughts on the key concepts discussed in the preceding chapters of this book. The book explores the complicated interrelationships among patterns in natural and cultural environmental variability, human demography, and human behavior that can be teased out of the archaeological and paleoenvironmental data from the Southwest. Most southwestern archaeologists seem to accept the notion that because of the region’s aridity and variability in the timing of rainfall, Precolumbian populations were always undergoing a moderate amount of stress. The book discusses the kinds of responses individuals and groups make to food scarcity. It also discusses the likelihood that indigenous Southwesterners used fire to enhance the productivity of edible woodland understory plant foods. The book also explores rainfall records on the eastern margins of the Pueblo world for patterns of complementarity and therefore mutually beneficial reciprocity among horticultural. It defines risk and the social and economic decisions that could be implemented with the intention of reducing risk.