[General Election Poll Verification - Jongno] 'Shy Conservative' Existed but Insufficient to Reverse Outcome

15 Polls from March to April... All Winners Predicted
No Survey Accurately Predicted Both Lee Nak-yeon and Hwang Kyo-ahn's Vote Shares Within Margin of Error
Both Candidates' Actual Vote Shares Higher Than Polls
Difference Between Polls and Vote Shares Larger for Hwang Than Lee

Graphic by Jin-kyung Lee, Art Reporter.

[Asia Economy Reporter Jin-Young Hwang] Various opinion polls conducted to gauge local public sentiment ahead of the 21st general election have been surrounded by controversy. The core of the controversy was that opinion polls failed to accurately capture public sentiment and instead distorted public opinion. Asia Economy is launching a series to verify how accurate the opinion polls were, focusing on constituencies where many polls were conducted.

The constituency with the most opinion polls conducted ahead of the 21st general election was Jongno, Seoul, where former Prime Minister Lee Nak-yeon and Future United Party leader Hwang Kyo-ahn competed.

As nationwide attention focused on this "preview of the presidential election," 15 opinion polls were conducted by various media outlets through specialized polling companies since the election campaign officially began in March.

All 15 polls predicted a victory for candidate Lee.

Although all polls predicted the election winner, there was a significant gap between the actual vote percentages and the poll support rates.

The actual vote percentages for candidates Lee and Hwang were 58.3% and 39.9%, respectively.

An analysis on the 20th of seven opinion polls conducted after the official campaign started on the 2nd showed that none of the polls predicted both candidates' actual vote percentages within the margin of error.

The discrepancy between the polls and actual vote percentages was found to be greater for candidate Hwang than for candidate Lee.

Candidate Lee's discrepancy ranged from -7.2 to 5.2 percentage points, while candidate Hwang's ranged from -13.2 to -2.8 percentage points.

Two polls showed candidate Lee's support rate higher than his actual vote percentage, whereas none of the polls showed candidate Hwang's support rate higher than his actual vote percentage; four out of seven polls underestimated Hwang's support by more than 10 percentage points.

It is possible that undecided voters shifted to support candidate Hwang, or as the Future United Party claims, there were some "shy conservatives"?conservative supporters not captured by the polls.

In any case, this is interpreted as not enough to overturn the election result.

Two polls predicted candidate Lee's vote percentage within the margin of error: one conducted by JoongAng Ilbo through Ipsos on the 7th-8th (Lee Nak-yeon 58.4%) and another by KBS through Korea Research on the 6th-8th (Lee Nak-yeon 59.4%). (For detailed information, refer to the Central Election Poll Deliberation Commission website.)

Two polls predicted candidate Hwang's vote percentage within the margin of error: one conducted by CBS and Kukmin Ilbo through Jowon C&I on the 4th-5th (Hwang Kyo-ahn 37.1%) and another by Seoul Shinmun through Research & Research on the 5th-6th (Hwang Kyo-ahn 36.9%).

The JoongAng Ilbo/Ipsos poll had only a 0.1 percentage point difference from candidate Lee's actual vote percentage, but candidate Hwang's support rate was 30.1%.

The difference between this poll and candidate Hwang's actual vote percentage was -9.8 percentage points, exceeding the margin of error (±4.4 percentage points).

The KBS/Korea Research poll was close to candidate Lee's actual vote percentage with a 1.1 percentage point difference, but candidate Hwang's support rate was 28.8%.

The difference between this poll and candidate Hwang's actual vote percentage was -11.1 percentage points, also exceeding the margin of error (±4.4 percentage points).

The CBS/Kukmin Ilbo/Jowon C&I poll predicted candidate Hwang's support rate most closely but underestimated candidate Lee's support rate by 6.1 percentage points, predicting 52.2%.

Unlike other polls where landline phone respondents accounted for about 10%, the CBS/Kukmin Ilbo/Jowon C&I poll had a landline phone respondent rate of 31%.

It is known that a higher proportion of landline phone respondents better reflects the voting intentions of voters aged 60 and above.

Among the seven polls conducted in Jongno in April, the CBS/Kukmin Ilbo/Jowon C&I poll showed the highest support rate for candidate Hwang and the second-lowest support rate for candidate Lee, following the Munhwa Ilbo/Embrain Public poll (Lee Nak-yeon 51.1%).

The Seoul Shinmun/Research & Research poll, which predicted candidate Hwang's support rate within the margin of error, predicted candidate Lee's support rate at 51.1%, exceeding the margin of error (±4.3 percentage points).

Three polls conducted from the 5th to 8th?SBS/Ipsos (Lee Nak-yeon 63.5%, Hwang Kyo-ahn 26%), Munhwa Ilbo/Embrain Public (Lee Nak-yeon 53.0%, Hwang Kyo-ahn 27.5%) on the 5th-6th, and Seoul Economic Daily/Embrain Public (Lee Nak-yeon 52.9%, Hwang Kyo-ahn 29.9%) on the 8th?showed support rates for both candidates outside the margin of error.

Even when expanding the analysis to eight polls conducted by media outlets in March before the official campaign period, none predicted both candidates' vote percentages within the margin of error.

The closest poll was conducted by JoongAng Ilbo through Ipsos on the 27th-28th of last month, showing Lee at 55.1% and Hwang at 34.5%.

The difference between candidate Lee's actual vote percentage and the poll support rate was 3.2 percentage points, within the margin of error (±4.4 percentage points), while the difference for candidate Hwang was 5.4 percentage points, slightly outside the margin of error.

Among the eight polls conducted in March, three showed candidate Lee's support rate within the margin of error compared to the actual vote percentage, and only one predicted candidate Hwang's vote percentage within the margin of error.

All eight polls underestimated the support rates for both candidates compared to the actual vote percentages.

However, the gap between support rates and vote percentages ranged from -10.0 to -1.1 percentage points for candidate Lee, and from -16.7 to -3.3 percentage points for candidate Hwang.

This indicates that candidate Hwang's support was relatively more underrepresented in the opinion polls than candidate Lee's.

This content was produced with the assistance of AI translation services.