The domestication of cargo-bearing animals contributed several important elements that transformed the nature of regional exchange relationships. First, there are some cross-cultural commonalities in the structure of contemporary societies practicing pastoralism, and it is probable that these factors had some role in prehistoric pastoral societies as well. Second, cargo-bearing animals transform the costs of transport and, consequently, the nature of long-distance interaction. Finally, the structure of wealth in animal herds conveys particular scalar advantages to powerful kin-groups that possess large herds. These factors condition long-term transformations such as sedentism, the nature of food production, and the institutionalization of social inequalities. These issues will be explored in three sections: household level articulation with agriculturalists, wealth accumulation among herders that is limited by risk and pasture, and caravans and the organization of pastoral labor.