New study tries to explain why phone and online polls are giving different EUref results
As we get closer to the referendum there’s a lot of effort going on to try look at the polling more closely so we don’t end with another GE2015.
The results of a Populus/Number Cruncher Politics study on the difference between the online and phone surveys was looked at on Newsnight last night and I’m hoping it will be possible to link to the actual document during the day. One of the conclusions relates to turnout and its link to demographics which is why I’ve featured the Ipsos-MORI GE2015 data in the chart above.
“The notion that Leave voters are more determined to vote in the referendum, based on what Leavers have been telling pollsters, has been little questioned. But this conclusion is heavily dependent on sampling people representatively in terms of relative political interest. Turnout self reporting is known to be misleading this far out. If instead we consider high and low-turnout demographics, older people are more likely to vote to Leave, but more affluent people are more likely to vote to Remain than less affluent people. In fact if we compare General Election turnout between constituencies, we find that turnout is not higher in more Eurosceptic areas â€“ in fact it is slightly lower. “
Another feature identified in the report is that those who respond to phone polls are more likely to give socially liberal responses than those online. Maybe that is the interviewer effect. Thus 40% of the phone sample felt that racial equality had not gone far enough compared with 24.9% of the online group. This compares to 31.9% in the huge BES face to face study.
One suggestion the authors make is that polls might be weighted by social attitude with, presumably, the BES being the norm.