how fast were the cars going when they bumped?
The first group reported significantly faster speeds. Words matter. • Refusal rates and truthfulness of responses: Some respondents refuse to answer pollster questions. If refusing to answer is correlated with voting for one candidate, then that candidate will be underrepresented in the polls. Some pollsters try to get at this problem by calling back repeatedly, but this in at best a partial solution. In some cases, voters may lie, although there does not seem to be a motivation to do so. The Bradley Effect is an instance of voters lying, but as reported above, seems to be a minor effect (if any) today. • Passage of time: Obviously, the polls are taken before the election, and voters may change their minds between the poll and election day.
