This is a continuation of my review and commentary of Joseph A. Tainter's The Collapse of Complex Societies (Cambridge Press, 1988). Here are the links to Part 1, Part 2, Part 3, Part 5 and Part 6.
... as a society evolves toward greater complexity, the support costs levied on each individual will also rise, so that the population as a whole must allocate increasing portions of its energy budget to maintaining organizational institutions. This is an immutable fact of societal evolution, and is not mitigated by type of energy source.
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It is the thesis of this chapter that return on investment in complexity varies, and that this variation follows a characteristic curve. More specifically, it is proposed that, in many crucial spheres, continued investment in sociopolitical complexity reaches a point where the benefits for such investment begin to decline, at first gradually, then with accelerated force. Thus, not only must a population allocate greater and greater amounts of resources to maintaining an evolving society, but after a certain point, higher amounts of this investment will yield smaller increments of return . Diminishing returns, it will be shown , are a recurrent aspect of sociopolitical evolution, and of investment in complexity.
Control and specialization are the very essence of a complex society. The reasons why investment in complexity yields a declining marginal return are: (a) increasing size of bureaucracies; (b) increasing specialization of bureaucracies; (c) the cumulative nature of organizational solutions; (d) increasing taxation; (e) increasing costs of legitimizing activities; and (f) increasing costs of internal control and external defense. These spheres are intertwined, and will be discussed together.
Organizational solutions tend to be cumulative. Once developed, complex social features are rarely dropped . Tax rates go up more often than they go down. Information processing needs tend to move in only one direction. Numbers of specialists ordinarily don't decline. Standing armies rarely get smaller. Welfare and legitimizing costs are not likely to drop . An ever increasing stock of monumental architecture requires maintenance. Compensation of elites rarely goes down. What this means is that when there is growth in complexity it tends to be exponential, always increasing by some fraction of an already inflated size.
Complex societies, by their very nature, tend to experience cumulative organizational problems. As systems develop more parts, and more complex interactions among these parts, the potential for problems, conflicts, and incongruities develops disproportionately. Mancur Olson has produced a good example of how complexity itself breeds further costs. Among contemporary societies, as regulations are issued and taxes established, lobbyists seek loopholes and regulators strive to close these. There is increased need for specialists to deal with such matters . An unending spiral unfolds of loophole discovery and closure, with complexity and costs continuously increasing (Olson 1982 : 69-73). Perrow ( 1984) has shown how in technological systems, the potential for catastrophic accidents increases solely by virtue of more complex linkages among parts . The cost of preventing accidents must therefore also rise.
Any complex hierarchy must allocate a portion of its resource base to solving the problems of the population it administers, but must also set aside resources to solve problems created by its own existence, and created by virtue of overall societal complexity. Prior to the development of modern welfare states it is likely that these increased administrative costs did little for the population as a whole other than to maintain some semblance of basic needs. And often even that was not accomplished.
To maintain growth in complexity, hierarchies levy heavier taxes on their populations . At some point even this yields declining marginal returns. This happens when rates are so high that avoidance increases , and taxation-induced inflation erodes the value of the money collected (Parkinson 1960: 79; Eisenstadt 1963: 1 52).
Rulers, as discussed in Chapter 2 , must constantly legitimize their reigns. Legitimizing activities include such things as external defense and internal order, alleviating the effects of local productivity fluctuations, undertaking local development projects, and providing food and entertainment (as in Imperial Rome) for urban masses. In many cases the productivity of these legitimizing investments will decline. Whatever activities a hierarchy undertakes initially to bond a population to itself (providing defense, agricultural development, public works, bread and circuses, and the like) often thereafter become de rigueur, so that further bonding activities are at higher cost, with little or no additional benefit to the hierarchy.
Per capita rates of economic growth decline with increasing GNP, so that as the economy of a society expands, its rate of growth slows down. Various economists (e.g. , Kristensen 1974; Rostow with Fordyce 1978) attribute this in large part to the cost of producing technical knowledge. It has been suggested that high growth rates use up the existing backlog of knowledge, so that growth thereafter must rely on the rate at which new knowledge is created. Growth, therefore, follows a logistic curve. Middle income nations develop a faster growth rate because they are able to simply absorb knowledge and technology developed elsewhere.(pp. 117-118). This, of course, explains the rapid development of certain economies, such as Japan in the early 20th Century, and China today.
In any event, Tainter explains that when a growing sociocultural system ultimately reaches a point of diminishing marginal return, "a complex society enters the phase where it becomes increasingly vulnerable to collapse." (p. 120).
There are two general factors that combine to make a society vulnerable to collapse when investment in complexity begins to yield a declining marginal return . First, stress and perturbation are a constant feature of any complex society, always occurring somewhere in its territory. Such a society will have a developed and operating regulatory apparatus that is designed to deal with such things as localized agricultural failures, border conflicts, and unrest. Since such continuous, localized stress can be expected to recur with regularity it can, to a degree, be anticipated and prepared for. Major, unexpected stress surges, however, will also occur given enough time, as such things as major climatic fluctuations and foreign incursions take place. To meet these major stresses the society must have some kind of net reserve. This can take the form
of excess productive capacities in agriculture, energy, or minerals, or hoarded surpluses from past production. Stress surges of great magnitude cannot be accommodated without such a reserve.
Yet a society experiencing declining marginal returns is investing ever more heavily in a strategy that is yielding proportionately less. Excess productive capacity will at some point be used up, and accumulated surpluses allocated to current operating needs. There is, then, little or no surplus with which to counter major adversities. Unexpected stress surges must be dealt with out of the current operating budget, often ineffectually, and always to the detriment of the system as a whole . Even if the stress is successfully met, the society is weakened in the process, and made even more vulnerable to the next crisis. Once a complex society develops the vulnerabilities of declining marginal returns, collapse may merely require sufficient passage of time to render probable the occurrence of an insurmountable calamity.
Secondly, declining marginal returns make complexity a less attractive problem solving strategy. Where marginal returns decline, the advantages to complexity become ultimately no greater (for the society as a whole) than for less costly social forms. The marginal cost of evolution to a higher level of complexity, or of remaining at the present level, is high compared with the alternative of disintegration. Under such conditions, the option to decompose (that is, to sever the ties that link localized groups to a regional entity) becomes attractive to certain components of a complex society . As marginal returns deteriorate, tax rates rise with less and less return to the local level. Irrigation systems go untended, bridges and roads are not kept up, and the frontier is not adequately defended. The population, meanwhile, must contribute ever more of a shrinking productive base to support whatever projects the hierarchy is still able to accomplish. Many of the social units that comprise a complex society perceive increased advantage to a strategy of independence, and begin to pursue their own immediate goals rather than the long-term goals of the hierarchy. Behavioral interdependence gives way to behavioral independence, requiring the hierarchy to allocate still more of a shrinking resource base to legitimization and/or control.
Thus, when the marginal cost of participating in a complex society becomes too high, productive units across the economic spectrum increase resistance (passive or active) to the demands of the hierarchy, or overtly attempt to break away. Both the lower ranking strata (the peasant producers of agricultural commodities) and upper ranking strata of wealthy merchants and nobility (who are often called upon to subsidize the costs of complexity) are vulnerable to such temptations. Effective political action on the part of peasantry can generally take place only when they are allied with other strata . This strategy is rarely employed, the usual course being recurrent peasant upheavals. Even still, peasantry can effectively weaken a hierarchy by other means when their marginal return for participating in a complex system is too low. A common strategy is the development of apathy to the well-being of the polity (Eisenstadt 196 3 : 207- 10). In both the later Roman and Byzantine Empires the overtaxed peasantry offered little resistance to the foreign incursions that ultimately toppled these regimes (A. Jones 1 964, ] 974; Charanis 1953: 420).
And so, societies faced with declining marginal returns for investment in complexity face a downward spiral from problems that seem insurmountable. Declining resources and rising marginal costs sap economic strength, so that services to the population cannot be sustained. As unrest grows among producers, increased resources from a dwindling supply must be allocated to legitimization and/or control. The economic sustaining base becomes weakened, and its members either actively or passively reduce their support for the polity. Reserve resources to meet unexpected stress surges are consumed for operating expenses. Ultimately, the society either disintegrates as localized entities break away, or is so weakened that it is toppled militarily, often with very little resistance. In either case, sociopolitical organization is reduced to the level that can be sustained by local resources.