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Comment by Osmium | Hacker News Reader

I think I speak for everyone when I say thank god politics is not like baseball :)

But seriously, congratulations to Nate Silver. I think this vindicates his method, at least for America. He was badly wrong with the last British election, whether because of bad polling data or an insufficient understanding of the system, so I was apprehensive going into this one. But it seems like, for America at least, he's cracked it. I think it's inevitable considering the absurd quantity of polling data available that someone would eventually.

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It shows how important it is to have experience and know your domain when you build a model and how understanding your subject matter is more important than cleverness.

Mr. Silver is one of the most clever people we have on the public stage, but that doesn't mean he has a silver bullet for everything. Rather, it enables him to work in a field that he knows very well and knock it out of the park.

2010 British Election (Number of seats)

Silver predicted: Conservative 312, Labour 204, Libdem 103 Actual result : Conservative 307, Labour 258, Libdem 57

This may have been because a) Clegg's performance in the first debate led to a lot of polls where LD support was high, but ultimately this support melted away by the election and the history bias kept polls wrong until the last minute, or b) because there were lots of Polly Toynbees telling pollsters "I'm voting lib dem" to make sure they were in with a chance in the coverage, but actually intending to vote Labour (she actually advocated this tactic of lying to pollsters in the Guardian.)

Either way, it shows that statistical averages of what people say they'll do isn't always a good indicator of what they'll actually do when push comes to shove.

Disclaimer: as a (now rather embarrassed) Lib Dem, I'd quite like these predictions to be more accurate so I don't get my hopes up again.

I think your explanation is reasonable, but that's no excuse.

His US model makes a lot of allowances for things like how self-proclaimed independents are likely to vote.

It didn't work as well in the UK though.

Indeed, I don't disagree. I'm just saying I think it may well be impossible to be completely accurate, or even remotely accurate, in crazy elections.

I have no idea about the political culture in the UK. Is it possible that he just didn't have as much data to work with? In other words, a lot fewer relevant polls to feed into a model?

we don't generally have very many regional polls, and certainly not constituency polls, that are available for aggregators (an internal poll in a key marginal, perhaps.) There's a lot less money spent on UK elections.

103 for the libdems! that's one of the funniests things i've seen for ages.

how did he get it so wrong?

Because lots of people lie to pollsters or change their mind based on the last thing they read in the paper?

In reading his analysis of the election here, he repeatedly mentions that having only two candidates makes things much more predictable.

In any case, we don't know if he got it "wrong" unless we know what % chance he gave this outcome. (He tries to account for the likelihood that polls are misleadingly biased, and that would correlate across multiple seats.)

>> I think I speak for everyone when I say thank god politics is not like baseball :)

politics is not nearly as important. :-)

Revenge of the Nerd. Sweet, sweet revenge :)

wasn't he badly wrong in the 2010 midterms? I'm not convinced this means he cracked anything. RCP uses simple average of polls, and they got 50/51 correct with Florida being the only wrong if it goes dem (which it looks like but hasn't been called).

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