Samuel Alexander — Resilience through simplification: revisiting Tainter's theory of collapse

2.2. Diminishing Marginal Returns of Complexity

At the centre of Tainter’s theory lies his idea that social complexity is an economic function that has diminishing marginal returns. Complexity is an economic function in the sense that it involves a balancing of costs and benefits. That is, when a society solves a problem by becoming more complex it will receive the benefits of solving the problem, but it will also incur the costs of doing so. These costs will include, most importantly, energy and resources, but also costs like time and annoyance. For example, when hunter-gatherer societies discovered agriculture and became aware that its methods could produce more food than foraging, they had to balance the benefits of transitioning to an agricultural society with the costs. The costs were that early farming techniques were more labour-intensive than foraging; the benefits were that agriculture was much more productive per acre, and this extra productivity might have provided a welcome opportunity to support non-food specialists or solved a society’s food crisis (perhaps brought on by overpopulation or overhunting depleting available resources).

This same balancing exercise takes place every time a society considers responding to a problem by creating a new institution, adding new bureaucrats, developing some new technology, or establishing some new social system, etc. Societies choose complexity – that is, choose to solve the problems they face – when it seems that the benefits of doing so will outweigh the costs. Critically, there must also be the energy and resources available to actually subsidise the problem-solving activity (or at least the potential to acquire more energy and resources, if current supplies are already exhausted in simply maintaining existing complexity).

Tainter’s central thesis, however, is that complexity is subject to diminishing returns, which is to say, over time the benefits of complexity diminish and the ongoing costs of maintaining or increasing complexity augment. He explains that this is because ‘humans always tend to pick the lowest hanging fruit first, going on to higher branches only when those lower no longer hold fruit. In problem-solving systems, inexpensive solutions are adopted before more complex and expensive ones’ (Tainter, 2011a: 26). In other words, over time increments of investment in complexity begin to yield smaller and smaller increments of return, which is another way of saying that the marginal return on complexity starts to decline....

Eventually, Tainter argues, the costs of solving a problem will actually be higher than the benefits gained. At this point further problems will not or cannot be solved, and societies become vulnerable to deterioration or even rapid collapse. Another way of expressing this is to say that there comes a point in the evolution of societies when all the energy available to that society are exhausted in simply maintaining the existing level of complexity. When further problems arise, as history tells us they inevitably will do, the lack of an energy surplus means that new problems cannot be solved and thus societies become liable to collapse.

Read it at Energy Bulletin
Resilience through simplification: revisiting Tainter's theory of collapse (part 1)
by Samuel Alexander | Co-director of the Simplicity Institute and lecturer with the Office for Environmental Programs, University of Melbourne