The same point keeps coming up in comments – if there is some great surge of young voters backing the Liberal Democrats, would it be picked up in the polls?

The short answer is that it should be. Pollsters in the UK do not weight their samples to match the demographic profile of voters, they weight them to match the demographic profiles of UK adults, so most of those young people who wouldn’t normally have voted should have been represented in the samples anyway. Only Harris specifically ask respondents if they are registered to vote, so they would not have been filtered out of other companies’ samples.

Another point I’ve seen raised is how well pollsters cope with young people who are predominantly online or have only mobile phones. Firstly, online really isn’t a problem, since we have plenty of online pollsters. Secondly, all polls weight by age, so this cannot result in an under-representation of young people. The problem would be if mobile-only young people were significantly different to young people with land lines. If landline penetration continues to fall I suspect that this will eventually be a problem that phone pollsters need to tackle, though there is always the option of including mobile phones in samples.

Perhaps the most common question I’ve seen is whether a change would upset pollsters “assumptions”. Pollsters do not assume particular groups are more or less likely to vote. Instead the majority of pollsters factor in likelihood to vote by asking people how likely they are to vote, and then weighting or filtering appropriately. The correct proportion of young people are already represented in pollsters samples, so if those people told pollsters they had become more likely to vote, it would be picked up.

The bottom line on a lot of questions of whether pollsters would pick up a new trend is that pollsters don’t actually make many presumptions up front about how people will behave. With a few minor and well evidenced exceptions (such as Populus and ICM’s reallocation of don’t knows on the assumption they are likely to vote how they did last time), voting intention figures are based on what people tell pollsters, not the pollsters’ preconceived assumptions.

Things can go always go wrong of course, and I expect it’s more likely to happen at an election where there has been a large shift in support, but I can’t see any particular reason to expect the polls to get it wrong this time.

104 Responses to “Young people and the Lib Dems”

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  1. Eoin

    You know that your reply on the students was slightly naughty as NI Uni’s have always had a very high percentage of local (NI) students compared to the local percentage of other Uni’s.

    Having said that I’m told that students all go home to M&D at the weekends nowadays (wimps), so maybe you’re right.

    What were are all tending to ignore is that the vast majority of young voters are not students. Even in the 18 – 21 age range, it’s only what 45%?

    Of course the student vote may be vital in some seats (you might have to eat your shorts over Exeter), but it’s whether and how the other 18-35 year-olds vote is the question.

  2. There are 166 Further education institutions in the UK

    Since we are saying that later registrations were

    a) all Lib dem
    b) all young
    c) all from universities
    d) all registered at universities
    e) the pollsters are not taking account of this
    f) this invalidates UNS

    are we now going to say

    g) But only registered at universities constituencies which are Lib D marginals?

    Guys, we need to catch ourselves on…..

  3. @Roger

    T’was a little naughty …….. :) But at least you’d sympathise with my scepticism.

    I went to University of Nottingham for my P.G.C.E. There were lots of utterly adorable young people from the home counties studying with me. I can report that they loved their mammies and daddies very much. :)

  4. Forgive me if this has already been discussed, but I would like to know about weighting on past vote. Do pollsters give less weight to those who have never voted (maybe because they were below 18 in 2005) or have not voted recently?

    If so, would this not underestimate the LD share if we assume many of the “surge” of new LD voters are the young, or “given up voting for the other two, but now might given the LDs have a chance” group?



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