From Joseph A. Tainters "The Collapse of Complex Societies" "The hypothetical society discussed a few paragraphs above responds to stress by increasing complexity. In so doing it increases investment in agricultural and other resource production, in hierarchy, in information processing in education and specialized training, in defence, and so forth. The cost-benefit curve for these investment increases at first favourably, for the easiest, most general, most accessible, however, continued stresses require further investments in complexity. The least costly solutions having been used, evolution now proceeds in a more expensive direction. The hierarchy expands in size, complexity, and specialization; resource production focuses increasingly on sources of supply that are more difficult to acquire and process; agricultural labor intensifies; information processing and training requirements become less generalized; and most likely, an increased military apparatus is seen as the solution to these problems. What benefits derive from these adjustments? Barring the acquisition of new energy sources, most often through conquest, such increased costs are usually undertaken merely to maintain the status quo. Stress that is met by increased complexity might come from such sources as agricultural deterioration, population growth, external danger, internal unrest, and threats to foreign sources of important commodities. When complexity increases to counter such stress, it achieves success when the factors that threaten stability no longer do so. So if agricultural production drops below about 2000 calories per person per day, increased complexity, and attendant agricultural development, may restore it to that level. Where stability is threatened by internal or external sources, increased complexity will achieve success when the prior state of orderliness has been restored, or the frontiers defended. Where the supply of a commodity is threatened, increased complexity and military adventures may ultimately secure an even greater supply of the commodity, but just as often they may not. Thus a growing sociocultural system ultimately reaches a point such as B1, C1 on the curve in Fig. 19, whereafter investment in further complexity yields increased returns, but at a declining marginal rate. When this point is reached, a complex society enters the phase where it becomes increasingly vulnerable to collapse." First published in 1988.