Squidginess and Homeostasis
In the good ol' days everything was straightforward. Difficulty getting from A to B? Build a new road. Population sick all the time? Build a sewage system. Economy moribund? Cut taxes and expand public spending. It was all sensible, linear stuff. Everything was mechanical and Newtonian: A leads to B leads to C leads to D. Cause and effect. Pull the lever; get the outcome.
It's all more difficult now though. Bloody climate change - hundreds of interdependent factors. Bloody obesity - millions of people all making their messy individual choices. Mental health crises at every turn - nightmare.
Complexity science is beginning to help, but as a culture we're still in the foothills of all this. In principle we know things like "in a complex open system it's best to identify a small number of key leverage points, which have a disproportionate effect on the overall behaviour of the system, and focus one's efforts on those leverage points", but actually identifying a leverage point, and then knowing what to do once you've found it - well, we've much to learn.
In the meantime, I find it helpful to think of it all as a bit squidgy. Like a big lump of springy tangled knotted stringy stuff. Push your finger in on one side, and it's probable that it'll squidge out somewhere else that will surprise you. Or, once you remove your finger, the indentation will disappear and may even extrude instead. Or the thing will retain its shape but will change its movement.
Messy messy messy.
One of the better-known illustrations of this sort of thing is something called the 'rebound effect'. This crops up a lot in the environmental field, where attempts to save the planet have often meant things like "a more energy efficient fridge" or "a hybrid car". The rebound effect means that, as fridges have become more energy efficient, they've gotten bigger. The savings that would have come from making all the fridges use less electricity have been reduced because people have bought bigger fridges (because they're cheaper than they used to be - they use less energy!).
Sometimes it can be subtler than this. There's sometimes a smugness effect (I've done the recycling or I've bought a hybrid car so I don't have to bother doing anything else) or, even worse, a compensation effect (I saved money by making environmental choice A, so I'm going to use the money to buy a foreign holiday, the environmental consequences of which dwarf the savings you made...)
You get the drift. A thing happens over here - and something else happens over there. Huh.
Anyway, just for fun, I've collected a few examples of squidginess - not all environmental - that might make you think:
Hurricanes make you live longer - American researchers looking at the effects of Hurricane Katrina discovered something remarkable. Many of the worst-affected areas were in the very poorest parts of New Orleans. Many people did not return after the hurricane but rebuilt their lives in new locations. Many of these locations were much better - better homes, better facilities - and people's health improved. So too did their life expectancy. Even including the harms caused by the initial disaster, the aggregate effect eight years after the event was a decrease in mortality of about 2% - which means, roughly, an extra year of life.
More television, less sex - collating survey evidence from nearly 4 million people in 80 countries, researchers demonstrate that, the more TV you watch, the less sex you have.
Calorie labels in restaurants affect starters but not desserts - research suggests that putting the calorie count on restaurant menus results in a 3% decline in calorie consumption, which sounds good. But it's clearly front-loaded - people notice when they're ordering starters, but have forgotten (or don't care) by the time they get to dessert. (This hints at the 'decay' effect seen elsewhere: the information has an impact to start with, simply because it's new; once the novelty wears off, you return to your previous behaviour...)
Fighting in a war increases your belief in God - researchers tracked large numbers of US service personnel and found that those that had actually been involved in combat, and especially those that had been wounded, exhibited dramatic increases in the frequency of attending religious service and of praying.
If your first car is 'green', you compensate by buying a 4x4 - researchers considered car purchase not in terms of single issues but in terms of 'bundles of attributes'. In a classic example of a rebound effect, they discovered that when the fuel efficiency of a first vehicle improved, people (in households with two or more cars) bought a bigger car or a heavier car for their second vehicle, often more than eliminating the benefits from the first car (a phenomenon known as 'negative rebound').
For your homework this week, look for other examples. Prizes for (a) the weirdest and (b) the most hopeful.