Major discrepancies between election forecasts and the final results of the June 3 local elections and National Assembly by-elections have sparked growing doubts about the accuracy of exit polls and pre-election surveys.

Polls ahead of June 3 local elections showed that results could vary sharply across polling firms, even when the same interviewer-administered telephone survey method was used.

In a stunning political turnaround, incumbent Seoul Mayor Oh Se-hoon has secured a victory in Wednesday’s local elections, overcoming an early exit...

Major discrepancies between election forecasts and the final results of the June 3 local elections and National Assembly by-elections have sparked growing doubts about the…