Election Simulations on 538
By: Stephen CollierPosted in Uncategorized, catastrophe models on July 26th, 2008
One of the blog phenomena of this electoral cycle has been 538, a blog written by a statistician who uses simulation techniques to create predictive models for electoral outcomes. I haven’t looked into the details, but in their broad structure these models are similar to the simulations that we have been looking at from the 1960s on in the context of defense and emergency management. They incorporate a bunch of electoral and demographic data, and then run simulations using a randomizer (like a Monte Carlo simulation). Effectively, this randomizer produces a large number of different “worlds” — which are just outcomes of the simulator. Back in the day it took weeks to run one such simulation. But now, with massive computing power, every time new data comes in — in the form of new polls — they plug them in and run the simulation again. It is then possible to run standard statistical analyses on the outcomes of these simulations, essentially treating them like an archive of past events. If you check out the charts on the right side of the home page, you see an “electoral vote distribution” graph. This essentially shows the number of simulations that produced a given outcome in terms of electoral votes. From this you get some probabilities that a given candidate will win or lose, but also win or lose with different combinations of state-level outcomes.
In fact, this sort of thing is becoming increasingly routine. I have seen similar techniques applied, for example, to baseball statistics. (One particularly interesting example was an attempt to use simulations to figure out how likely it was that the record for consecutive games with a base hit would be tied or broken — the answer is fairly likely). And this is definitely the technique used in many formal catastrophe models.
It’s hallucinatory Friday in VSS land — and that must mean DARPA. Wired has an