"It can't be done"
A common objection against this is that human behaviour cannot be modelled. Of course, as a model-building economist I don't agree with that. Economists have a large set of quantitative models at their disposal that describe human behaviour at several different spatial scales, from consumer choices to entire economies or even international trade. Some biologists at the meeting explained that similar objections were made when biologists started developing their own ecosystem models, but that has never stopped such models from proliferating. Why would humans be any different? The discussion set me thinking about the similarities and differences between humans and fish, and how they could make modelling human behaviour easier or more difficult than modelling animal behaviour or ecosystems.
Why humans are like fish
Basically we discussed three objections that were made against biological models, and are now made against modelling humans. First, people object that the object of the model is too complex. That's true, but so are the global climate, the cascade of nuclear fission and fusion in a hydrogen bomb, and a horde of blood-thirsty zombies climbing over a 50 meter high wall. But that never stopped people from modelling these processes in a plausible manner (admittedly, one of these examples is fictional and no, it's not the first one). If we don't model these processes we will never understand them or how they interact with other processes.
|In the fish tank|
A third objection is that models tend to induce tunnel view, where effects that are not "in the model" are ignored. This is a fair point, and as an economist I must admit that my profession has not been immune to this effect. So we need a diverse ecosystem of theories, approaches, and models, in order to stay open-minded for arguments or effects we hadn't thought of. Again, this objection has also been made with respect to biological models, and it has never stopped biologists from modelling.
Why humans are not like fish
This is where it gets interesting. First of all, fish don't read. People, however, may read your report and respond. There is evidence that negative news coverage on consumer confidence further reduces that same consumer confidence. This is a typical feature of social science research: as a researcher you have an impact on your object of research (i.e. people) that goes much deeper than any quantum physicist could get. Your results could be self-fulfilling, as in the consumer confidence case. They could also be self-defeating, as some people argued was the case with Limits To Growth: the stir caused by this report inspired efforts to reduce pollution and resource use to such an extent that we evaded the environmental catastrophe predicted by the report. (I'm not sure I'm buying the argument about this particular example but you get the idea.)
Second, I would argue that humans are much better at anticipating what other humans, including governments, do. For example, a common objection against vessel buybacks is that they create an expectation among fishers that the government will buy access capital (at tax-payers' expense) when the going gets tough for fishers - an open invitation for creating excess capacity because fishers face only part of the financial risks. Likewise, fishers may anticipate what other fishers do in their decision whether to fish, and how much to fish.
|Who needs a window if you can have a view on virtual nature?|
Fourth, on the bright side, we cannot communicate with fish but in social research we can do surveys and interviews to gain insight into their considerations, their lines of reasoning, and so on. These methods are not perfect (people can lie, or withhold information), but neither are biological measurement tools such as the ones used in stock assessments.
Should we? Can we? How?
The bottom line is that we can to some extent model human behaviour, and by doing so we can address a lot of pressing problems. But it will be tricky. I can't judge whether it will be trickier than modelling fish, but it will surely be tricky in different ways. Again, that should not be an impairment to doing it.