Yesterday Wired published an article by Klint Finley, Mathematicians Predict the Future With Data From the Past. Apart from a couple of minor details Klint does a good job explaining the goals and the methods of Cliodynamics. However, he (or his editor; it is almost always editors who come up with titles) couldn’t resist injecting a bit of sensationalism by implying that Cliodynamics can predict the future. I don’t blame him – it’s part of the business they are in. But here, in my blog, where I have no editors over me and nothing to sell, I want to make it absolutely clear that
CLIODYNAMICS IS NOT ABOUT PREDICTING THE FUTURE!
The future is not predictable, except in a most trivial sense (yeah, in 2020 the Earth will be circling around the Sun. If it’s not, we will be part of an expanding radioactive dust cloud, so the last thing I’d care about would be the failure of my ‘prediction’).
Cliodynamics, instead, is about understanding why and how social systems change. We look for general principles (‘laws’, if you will), and build mathematical models based on these principles. Then comes the most critical part – testing model predictions with historical data so that we can tell which models and theories are correct, and which are not. So prediction is instrumental – it is subordinated to the main goal, that of understanding. The chief purpose of mathematics is to make sure that predictions really follow logically from the premises. Otherwise, we could wrongly reject a theory, if we mistakenly test a prediction that doesn’t follow from it.
It is useful to distinguish this kind of prediction, which is subordinated to the main goal of testing theories (I’ll call it ‘scientific prediction’) from prophecy. A prophecy is an unconditional statement of what will happen in the future. For example, ‘life on Earth will end in 2012.’
Another one is ‘the United States will collapse in 2020.’ To my great amusement, there are ‘reporters’ out there who claim that I propounded such a prophecy!
For the record: I never said it. It might happen – great empires did collapse in the past – but the probability of such an event in the next 10 years, in my opinion, is pretty low. In any case, the structural-demographic model that I have developed for the United States predicts no such thing (details in my forthcoming book on the structural-demographic analysis of American history; the current series of blogs on the dynamics of real wages describes one of the components of the model).
What the model does predict is that, given the trends of major structural-demographic variables over the past 40 years, we are due for a fairly major wave of sociopolitical violence – unless something changes. This ‘something changes’ sounds weasely, but actually the model says what needs to be done to avoid the outbreak of instability – reverse the trend of growing income inequality, moderate intraelite competition, get the state finance back into balance, and so on.
So the ‘bad news’ is that the future is unpredictable. But, as I said in a previous blog, prediction – or, rather, prophecy – is overrated. What’s the use knowing that doom is upon us, if there is nothing you can do about it? Wouldn’t it be better to understand the causes of the looming danger, so that we could take steps to avoid this undesirable future?
Other blogs on similar issues:
Notes on the margin: Starting today and through the weekend I am hosting the evolutionary biologist Michael Rose. So it will be a few days before I am able to get back to the next installment of the real wages series.