"Science and Art" Praised Exit Polls: Will They Be Worth 7.2 Billion Won in the General Election? [NewsSeolCham]

⑬Exit Polls Accurate Within 0.1%p, This Time?
Presidential Elections Always Accurate... General Elections with Sample Shortages May Have Errors
Variable: High Early Voting Rate... Increasing Turnout Trend in Every Election
Three Broadcasters Spend 7.2 Billion Won on Exit Polls for This General Election Too

Editor's Note'Seolcham' is a newly coined term meaning to refer to detailed explanations. In [News Seolcham], we aim to pinpoint and explain in more detail the parts of the news that require fact-checking or further explanation.

"Exit polls are both a science and an art." (Jin Jung-kwon, former professor at Dongyang University)

Will the exit polls by the three major broadcasters (KBS, MBC, SBS), which received praise for accurately predicting results down to decimal points in the last presidential election, continue their 'spot-on' reputation this time as well?

Broadcast exit polls were introduced in 1995 during the first simultaneous local elections nationwide. Since then, exit polls have been conducted five times in presidential elections from the 16th to the 20th and six times in general elections from the 16th to the 21st. Previously, each broadcaster conducted exit polls individually, but since 2010, the three broadcasters have jointly conducted exit polls.

Voters Participating in Early Voting for the 22nd General Election

◆ Presidential Election Exit Polls: 100% Accuracy in Predicting Winners from the 16th to 20th Presidents

Since 2002, the three broadcasters' presidential election exit polls have correctly predicted all outcomes. While the expected vote percentages for each candidate differed slightly from the actual counting results, the winner and the ranking by votes were always spot on. During the 16th presidential election, the three broadcasters conducted exit polls individually and announced their results, all correctly predicting the victory of Roh Moo-hyun, then the candidate of the Millennium Democratic Party. Among them, KBS predicted the results most accurately, forecasting that candidate Roh and Lee Hoi-chang of the Grand National Party would receive 49.1% and 46.8% of the votes, respectively. The actual count showed Roh receiving 48.91%, beating Lee by a margin of 2.33 percentage points.

In the 17th and 19th presidential elections, where the gap between the first and second candidates was large, predicting the outcome was relatively easier. However, forecasting the vote percentages remained challenging. In the 17th presidential election in 2007, all three broadcasters predicted that Lee Myung-bak of the Grand National Party would secure a majority, but the actual vote count showed Lee receiving only 48.7%. However, the vote percentage for Chung Dong-young of the United New Democratic Party was closely predicted (MBC and KBS estimated 26.0%, actual 26.1%). In the 19th presidential election, candidate Moon Jae-in won with 41.0% of the votes, which was only 0.4 percentage points different from the broadcasters' prediction of 41.4%.

In the 20th presidential election held in 2022, the exit polls showed an extremely high accuracy rate with a difference of just 0.1 percentage points. It was at this time that Jin Jung-kwon's praise of exit polls as "a realm of science and art" emerged. The three broadcasters predicted that candidate Yoon Seok-youl would receive 48.4% and candidate Lee Jae-myung 47.8% of the votes. The actual results were Yoon 48.6% and Lee 47.8%, almost identical.

◆ General Elections Are Difficult to Predict and Often Miss the Mark

However, in general elections, the exit polls have often faltered. This is because the number of constituencies where exit polls are conducted reaches 254, and the sample size per individual constituency is smaller than at the national level, making accurate predictions difficult. In the 19th general election held in 2012, MBC was the only broadcaster to correctly predict the Saenuri Party's seat count (152 seats), forecasting a range of 130 to 153 seats. All three broadcasters missed the Democratic Party's seat count prediction. In the 20th general election, MBC and KBS expanded their predicted range from about 15 seats to up to 24 seats, successfully predicting the seat counts for the two major parties.

In the most recent 21st general election, the introduction of the semi-proportional representation system required predictions that included satellite parties. The combined expected seat counts for the Democratic Party and the Together Citizens' Party were ▲KBS 155?178 seats ▲MBC 153?170 seats ▲SBS 154?177 seats, but the actual count was 180 seats. For the United Future Party and its proportional satellite party, the Future Korea Party, the expected ranges were ▲KBS 107?130 seats ▲MBC 116?133 seats ▲SBS 107?131 seats, while the actual seat count was 103. Although all three broadcasters successfully predicted that the Democratic Party would secure a majority, they failed to accurately predict the exact number of seats.

Since the 2016 general election, the early voting system has introduced a new variable affecting the accuracy of exit poll strategies. Because exit polls for early voting are prohibited by election law, an additional task is to adjust for differences between early voting and main voting results. Generally, early voting tends to show higher vote percentages for Democratic Party candidates compared to main voting. Regionally, the Honam area shows high early voting enthusiasm, while the Yeongnam area has low early voting rates, a phenomenon known as 'Hogo-Yeongjeo' (high Honam, low Yeongnam). In the 22nd general election, Jeonnam and Jeonbuk ranked first and second in regional early voting rates at 41.2% and 38.5%, respectively. The lowest early voting rate was in Daegu (25.6%).

Moreover, the early voting rate, which was 12.19% when first introduced in the 20th general election, has set new records in each subsequent election: ▲21st election 26.69% ▲22nd election 31.28%, increasing the difficulty of prediction. Approximately half of the total expected voter turnout of around 60% occurs through early voting. The three broadcasters and polling agencies apply correction factors based on telephone surveys of early voters.

The three broadcasters will conduct joint exit polls again in this general election. A total budget of 7.2 billion KRW has been allocated. The Korea Broadcasting Association's Joint Broadcasting Prediction Survey Committee (KEP), which includes the three broadcasters, will conduct exit polls on election day, the 10th, at about 2,000 polling stations nationwide, surveying approximately 500,000 voters, and announce the results through the three broadcasters at 6 p.m. on the same day. The executing agencies are Korea Research, Korea Research, and Ipsos Corporation.