Modeling "Wicked" Cumulative Effects

Cumulative Effects
By J.B. Ruhl

In several posts earlier this month I explored the difficulties presented by "cumulative effects" problems such as global climate change. Here I outline a model of the essential characteristics of the most complex cases of such effects--the "wicked" problems that present the hardest management challenges for social, economic, and legal institutions.

• Massive source agent numbers: Cumulative effects problems are likely to be easier to manage when the number of agents contributing to the effects is small. We have a realtively small set of coal fired power plants emitting greenhouse gases, for example, but a much larger set of agricultural land uses contributing to nutrient runoff affecting the "Dead Zone" in the Gulf of Mexico. No surprise that we blanket power plants with regulations (some say too much, others say not enough) whereas farms are relatively untouched by environmental regulation, if not deliberately left alone.
  

• Nonlinear aggregation thresholds: The aggregation of effects as agent numbers increase and agent behavior consequences accumulate may not exhibit proportionalality over time and space. The effects, may begin to exhibit synergistic interactions that amplify or impede the cumulative effects or reveal new qualities to the effects. These "jumps" in quantity and quality may present themselves at relatively discrete thresholds along the way. Predicting when these nonlinear thresholds will occur is likely to be very difficult.
  

• Source agent resistance to change: The behavior of the source agents leading to the cumulative effects may may have nothing to do with wanting to cause the effects, but rather the effects may be the incidental consequence of behavior that is motivated by some deeply rooted incentives or set of circumstances. In complex systems terminology, the agent behavior is self-organizing around attractors, and bumping the behavior out of the attractor can be quite difficult. The source agent behavior, in other words, may have deeply sunk "roots."
  

• Coevolution with other agent systems: It is entirely possible that the cumulative effects produced from one source agent system begin to coevolve with other agent systems in such a way as to reinforce the other or vice versa. The source agenct system, in other words, may spread "tentacles" between other systems, which may make it difficult to disentangle the root cause of the cumulative effects or, once identified, to uproot it without affecting other systems.
  

When all these characteristics are in play, we've got a nasty problem on our hands.

Perhaps, however, this is all just a matter of degree, not of quality, and the solution is to throw more of the same at the problem. Maybe, for example, the best way to deal with wicked cumulative effects problems is through the most elegant complex adaptive system devised by humans--markets. Or, at the other end of the spectrum, perhaps the rational administrative state should confront such problems through regulation guided by aggressive use of cost-benefit analysis of policy options.

In the next few posts I will argue that, while market-based approaches and cost-benefit analysis have a role to play, expecting either to supply the complete answer is preposterous.