“There
is a pro-Labor and anti-Conservative bias in polls.”
Two
examples of “herding” in the 2014 election appeared in the Kansas and
Virginia Senate races. Pollsters there didn’t release their numbers
because they deviated too much from what others showed. In that way,
Virginia voters were badly served because no late published poll caught
Republican Ed Gillespie’s last-minute surge that almost defeated
Democratic incumbent Mark Warner.
This is playing with dynamite. Pollsters in Britain have long realized
the potential polling problem created by the “shy Tory” vote —
referring to those voters who don’t want to admit to pollsters that
they are going against the grain of media coverage and might cast a
politically incorrect vote. But this is the third time in 50 years that
the shy Tories have swung an election (it also happened in 1970 and
1992). Apparently, polling companies haven’t been able to solve the
problem. Chris Hanretty, the academic who advised the BBC on polling,
told Britain’s Guardian newspaper that he feels “a little bit foolish,”
in the wake of the election. “We categorically ruled out a
[Conservative] majority. . . . We should have expected far more ‘shy
Tories.’”
Pollster Stephen Fisher also told the Guardian that the problem is more
complex than that. Noting that polling companies have consistently
exaggerated the Labor vote since the 1970s, he concluded: “Polling
companies have done a lot of work to try to counteract this, but it
keeps happening. There is a pro-Labor and anti-Conservative bias in
polls.”
