Clay Shirky writes,

Complex societies collapse because, when some stress comes, those societies have become too inflexible to respond. In retrospect, this can seem mystifying. Why didn’t these societies just re-tool in less complex ways? The answer Tainter gives is the simplest one: When societies fail to respond to reduced circumstances through orderly downsizing, it isn’t because they don’t want to, it’s because they can’t.

In such systems, there is no way to make things a little bit simpler – the whole edifice becomes a huge, interlocking system not readily amenable to change. Tainter doesn’t regard the sudden decoherence of these societies as either a tragedy or a mistake–“[U]nder a situation of declining marginal returns collapse may be the most appropriate response”, to use his pitiless phrase. Furthermore, even when moderate adjustments could be made, they tend to be resisted, because any simplification discomfits elites.

When the value of complexity turns negative, a society plagued by an inability to react remains as complex as ever, right up to the moment where it becomes suddenly and dramatically simpler, which is to say right up to the moment of collapse. Collapse is simply the last remaining method of simplification.

Thanks to Laura Freschi for the pointer. Naturally, when somebody mentions the possibility of a system becoming overly complex, maladapted, and unable to simplify itself, I think of contemporary government in the United States.