The Financial Times’ latest poll of polls had a Remain-Leave-Undecided ratio of 48%-46%-6%. The Economist’s tracker had 44%-44%-9% (not sure where the missing 3% went). The actual vote went 52%-48% for Leave. Were the polls misleading or misinterpreted?
First, the polls may have accurately estimated the breakdown among the public in general but not among those most likely to vote. Second, the undecided may have made all the difference on the voting day. In any case, the six percentage point discrepancy between the Leave-Remain difference in the FT’s aggregate poll and in reality – between -2% and nearly +4% – cannot be waved away as a statistical blip.
It’s possible the polls influenced the voting. Some people didn’t bother to vote Remain because they thought it was in the bag. Others tried to protest vote tactically – they didn’t actually want to Leave but they only wanted Remain to win by a small margin to send a message to Brussels. Unfortunately, this plan proved to be not so cunning after all.