peterbirks: (Default)
[personal profile] peterbirks

 I have long been fascinated by opinion polls -- indeed, by statistics in general. That I am hopeless at the mathematical side of statistics just adds to my fascination.
Opinion polls seek to guess how people in their millions will act on the basis of relatively small samples. It was immediately obvious that just asking 1,000 people at random in the street would be at risk of generating an erroneous response (although the degree of that likely erroneousness is possibly less than many would think).
Pollsters realized that a good way to increase the accuracy would be to ensure that the sample of 1,000 people reflected as much as possible the population as a whole - age distribution, sex distribution, and so on.
This, however, leads to another problem. Over the years it was discovered that, shock, horror, what people said was not always the same as what they did. Even more concerning, what people really believed was often different from what they did (the famous female claimed belief in what attracts them to a sexual partner/life partner differs drastically from empirical evidence of whom women actually choose). The ways in which questions were phrased also had a significant impact on the response.
Clearly, opinion polling was something of a nightmare. And, given the misperformance of the pollsters leading up to the last general election in the UK, the pollsters still haven't got it right.
So, what is it that they are getting wrong?
The two major problems are the aforementioned "tendency to deceive" (people respond with what they think they ought to say, rather than what they really feel) -- a factor that has been a curse for the intellectual left-wing for decades. These days they flood Twitter and Facebook, demonstrate to their own satisfaction that the argument has been won, and wake up the day after voting to have been told "fuck off". The secret ballot allows visceral emotions to come into play. A person might not vote for a candidate because he or she doesn't like the fact that the candidate is fat. But no respondent to an opinion poll is likely to say that, and no online social media campaign is going to mention "the elephant in the room" if a candidate is 25 stone-plus and female.
The second problem is more complex -- one that is only just coming to be fully appreciated. That is, how do you decide what is a "representative" sample?
In the early days of polling, the techniques were primitive - mainly age and sex. This came most unstuck in 1948 in the US, when a telephone poll predicted that Harry Truman would lose. As seems obvious now, the key was in the phrase "telephone poll". With a market penetration still under 50%, people with a telephone were markedly more likely to be better off, and, therefore, Republican voters.
So, clearly we have to add "income" to our representative mix. In fact, what pollsters need to do is to add any variation in the make-up of the general population that is positively correlated with the way that people are likely to vote.
You can see the problem here. This in itself is something of a judgment call. As it is a sample, the pollsters must by definition filter out "irrelevancies". The problem appears to be that in a dynamic society, some things that used to be relevant have ceased to be so, while other things which did not use to be important, now are.
With the referendum, where "all bets are off" when it comes to traditional party politics, the problem is multiplied. What on earth is "relevant" when it comes to picking a true representative sample, when the split is not along traditional party lines? Also, there appear to be significantly more "elephants in the room" -- things which neither side are prepared to mention, but which could be significant factors when it comes to voting. That in turn feeds back to a higher likelihood of a "propensity to deceive" and a greater danger that the phrasing of the poll question will distort the result from reality.
I'd quite like to see some sample results from randomly asking 200 people each in, say, five streets in England. I suspect that the numbers obtained would not be a long way different from the carefully calculated "representative samples".
In poker I have long argued that you can learn more from small samples than you think. The conventional wisdom in poker is that you can't learn anything from, say, a player's actions over five hands. I argued, way back in the early 2000s, that if this was all that you had to work with, ignoring it was stupid, just because there was a higher probability that the answer you obtained would be wrong. Sure, with five hands the standard deviation is many times higher than it would be on a sample of 50, 500 and 5,000. But it is not TEN times higher than the sample of 50 - it's closer to three. It is not a thousand times higher than a sample of 5,000 -- it's closer to 80.
Sure, the conclusion you reach if the player raises four times and folds once in his or her first five hands might be erroneous. But the probability that this player is loose-aggressive is still significantly higher than it was when you had a sample size of zero.
In other words, completely random samples (and I mean virtually completely -- no self-selection on the basis of sex and age and only a minor one on grounds of geography) might have their place. And they have one plus -- they are much easier, quicker and cheaper to compile.

Peter Kellner, in his blog, referred to an interesting statistc -- that being the percentage of people who see Brexit as a "risk" compared with Remain as "safe". The rough percentage appears to be that 10pp more people see Brexit as the "risk option".
This offers an interesting left-field take on the referendum. It means that 10pp of the "Remain is safer" believers, or 5% of voters, would need to think that Brexit was "a risk worth taking", to make Brexit the likely winner. The remaining voters would be committed to Brexit or Remain either way. That 1-in-20 number strikes me as uncomfortable reading for Brexiters. Look at the general population's attitude to risk-taking on a major level. Nearly all of it is about risk-avoidance. Indeed, the huge risks that they do take are usually ones that they take unwillingly and, not infrequently, without the knowledge that they are taking the risk (see 40-year mortgages, Equitable Life, negative equity in the early 1990s). When a risk is known and perceived, and conceived to be significant, people usually plump for safety.
From that point of view, the Remainers' best argument could well be the one that they are uncomfortable to make -- that, even if being in the EU is shit, the equivalent of an abusive relationship -- even if this is the case -- we are now so inextricably tied into the EU that the risk of leaving is too great. That, no matter how bad it is, leaving would be too big a risk.
This is what I mean by "the elephant in the room". It's probably Remainers' strongest argument, but it is one that no Remainer is willing to accept exists (or, if they are, willing to campaign on it).

Date: 2016-06-08 10:55 am (UTC)
From: (Anonymous)
Interesting, since that "risk worth taking" sums up my view entirely. Yes leaving the EU a risk, but IMO the bigger risk is walking with eyes open into the, to my mind, inevitable smash up that's coming. The metaphor that I'm using is that yes, I know that jumping into the lifeboat will be cold, miserable and doesn't guarantee survival, but it's still better than staying on board a ship driven by people who seem determined to sail into the rocks, and have proved that no amount of rational argument will cause them to change course. So maybe I'm just an outlier, or maybe there are more risk takers around than you think. John W

Stats

Date: 2016-06-08 06:06 pm (UTC)
From: [personal profile] cerebus
All a bit esoteric when it comes down to the "arguments" on each side, innit? Statistical analysis isn't just difficult for you and I -- it's practically impossible for the man in the street. Ask them to predict the statistical likelihood of any given immigration percentage in, say, 2017, and they'll be stumped.
But they'll still "know" that, in some way, "it will be bad."
Now add a further mind-bender into the equation. What are the main factors driving net immigration?
a) The open frontiers of the EU
b) The pull factors of "a better life than Iraq/Yemen/Afghanistan/Nigeria."
The man in the street will assume -- I think; I've argued this down the pub -- that the massively dominant factor is (1).
But what if it's (2)?
All you end up doing is to swap EU immigrants with West African immigrants. Now, given that Nigerians (for example) are one of the more successful immigrant groups in terms of basically doing the hard yakka ... that might actually be a good thing.
But second order effects are not really what this referendum is about, are they?

Machine Learning

Date: 2016-06-08 06:15 pm (UTC)
From: [personal profile] cerebus
Incidentally, the presumptive solution to your Harry Truman/Judgement Call issue is really very simple.
Don't let humans normalize for population bias. Let machines do it.
This is, after all, essentially the sole intellectual principle behind Google and Bing and other search engines. (Billions of dollars of processing power helps, but we're talking a far more limited domain here.)
Humans will inch forwards according to their own biases. Gender this decade. Race the next. And so on.
Machines will exercise a purely neutral ranking, given (in the representative cases of Bing and Google on yer average query) something like SEVENTY possible signals.
I don't believe anybody has applied ML to polling techniques yet, but I suggest that the technology is just about mature to use.

Date: 2016-06-24 02:49 pm (UTC)
From: (Anonymous)
Two articles of obfuscation to justify nothing.

Too late mush. We're leaving anyway.

No thanks to self-loathing wet liberals like yourself.

Date: 2016-06-24 11:04 pm (UTC)
From: (Anonymous)
This was not a trivial decision and it deserved consideration - liberal, wet or otherwise. Meanwhile, it is typical of the EU that David Cameron has resigned, but Donald Tusk and Jean-Claude Juncker have not. The EU has mislaid one of its largest net contributors, which has huge implications for its finances, whilst other countries may also decide to leave. This happened on their watch and is the product of the EU's "refusal to engage on real issues" and their minimalist approach to reform/change. They probably enjoyed watching David Cameron return to face his electorate armed with the skimpiest of reforms and had no thought for the possible consequences. Even now the EU line is that it is business as usual for the remaining 27 members.

But, hey, the EU is run by people who know better and don't need to listen because they are not elected. Niall L.

Date: 2016-06-25 02:45 pm (UTC)
From: (Anonymous)
Peter Birks ‏@peterjbirks 20h20 hours ago Lewisham, London

"It appears that the majority of Sunderland residents who voted "leave" thought it meant they would be getting out of Sunderland."


Oh, it's one of those delightful middle-class lefty jokes aimed at working class labour party voters who don't do what is expected of them.

Get out the horse whip!

You ignorant tosser.

Date: 2016-06-27 09:16 am (UTC)
From: (Anonymous)
The left seems to understand reality about as much as I do quantum physics.

Hilarious watching them do a U-turn on Corbyn. A God one moment, a sod the next.

There they all were camping outside St Pauls, protesting against the 1%. The next moment they are in bed with the 1% and the TTIP supporters over Brexit.

They grudingly accept a Tory government with 37% of the vote but want to over-turn a 51% majority vote.

No World War 3, no financial market melt-down.

Time for lefties to stop taking hallucinogens and face reality.

When bankers and corporate leaders tell you what to do then surely you must smell a rat??? All they care about is themselves. You mean nothing to them.

Date: 2016-06-29 08:36 am (UTC)
From: (Anonymous)
Birks turned his back on his working class roots so that he could join the SMIRKING CLASS.

Date: 2016-07-02 12:02 pm (UTC)
From: (Anonymous)
"I love Europe"

"I am a free-trader"

Surely Birks is not stupid enough to think that Brexit voters hate Europe. The EU and Europe and not the same. Brexit voters know that they are European but that they want a better Europe than the EU can provide.

Does Birks think that free-trade will cease? For EU nations to stop trading with the UK will be case of shooting themselves in the foot.

When you live life on Twitter or Facebook you highten your isolation by associating only with like-minded people.

Birks, you have created a bubble of unreality around you. A Jobsian Unreality Distortion Field.

Maybe you are going through a mid-life crisis and want to "identify" with young people. A life gone to waste. No wife. No children. You want to feel that you have achieved something but you never will.

June 2017

S M T W T F S
    1 23
456 78910
11121314151617
18192021222324
252627282930 

Most Popular Tags

Page Summary

Style Credit

Expand Cut Tags

No cut tags
Page generated Aug. 21st, 2017 12:47 am
Powered by Dreamwidth Studios