This is possibly the best overall review of the processes by which tribal peoples developed chiefdoms, which later gave rise to early states. This is not surprising given the central role played by Robert L. Carneiro in generating some of the earliest and most substantial studies of this historically crucial socio-cultural process.
Carneiro begins by providing a summary of his and other theories on the origin of chiefdoms and states, and goes on basically to support his previous positions and similar versions described by numerous other scholars. For this reason, the essay provides a useful review of sociocultural developments leading up to the earliest as well as the later state formation process. For those scholars not well versed in this literature and argument, the essay will be highly educational and enlightening.
The core of the essay, however, is Carneiro's attempt to bolster his claim that chiefdoms and later states emerged within circumscribed settings created by reduced physical space, unusually important lakes and rivers, highly valued natural resources, etc. He continues to argue that in addition to natural features, population crowding and especially warfare were always factors that incited the process of centralizing authority. He especially emphasizes the role of warfare in the centralization of the political structure, even though he argues that no single factor can account for the widespread process of chiefdom formation.
The essay is uniquely valuable for the numerous case studies describing the process of chiefdom and state formation. None of his case studies is presented in detail, but all of them seem particularly relevant and their diversity supports his thesis that the process is complex but nevertheless based on diverse forms of circumscription.
My only reservation with respect to his analysis and summary is the little attention given to cultural factors, especially those of a religious nature. The pervasiveness of religious thinking in the tribal world was so pervasive that it seems inconceivable it would not have been a highly significant factor in the coalescence of the earliest chiefdoms and states. Most of the classic cases of chiefdoms and early states point to the extremely close relationships between centralizing authorities and their religious beliefs and unifying claims. This factor is mentioned by Carneiro, but it receives limited attention compared to ecological and economic factors.