"South Korea's Exit Polls at World-Class Level"... Variable Is Record High Early Voting Rate

"Presidential Election Exit Polls Accurately Predicted Winner All 5 Times"
"General Election May Have Margin of Error... Due to Small Sample Size in Districts"

With the early voting rate for the April 10 general election reaching a record high of 31.28%, attention is focused on the exit poll accuracy of the three major broadcasters (KBS, MBC·SBS). Kim Chun-seok, head of the public opinion research division at Hankook Research, stated on the 9th, "Since 2002, we have conducted exit polls for presidential elections and have never been wrong about the winner," adding, "The level of exit polls in our country is the best in the world."

On the same day, on KBS Radio's 'Jeongyeok Sisa,' Kim said, "The largest margin of error in presidential election exit polls has been around 3%," and "You can consider that presidential election exit polls do not get the winner wrong." However, he noted that for general elections, since the sample size per individual electoral district is smaller than at the national level, the accuracy rate may be lower. Kim explained, "In the last general election, out of 253 electoral districts, 14 districts were incorrectly predicted," meaning the winner was not identified within the margin of error.

Kim explained, "Typically, there are 55 polling stations per electoral district, and among these, 7 to 8 polling stations are randomly selected to survey the fifth voter who votes at each polling station," adding, "This is to ensure that the thoughts or intentions of the surveyors do not influence the results." He further added, "Out of about 14,000 polling stations nationwide, surveys are conducted at approximately 2,000 polling stations, resulting in a total sample size of about 400,000 to 500,000 people."

On the afternoon of the 5th, a citizen is voting at an early voting station set up at the Samdeok-dong Administrative Welfare Center in Jung-gu, Daegu. [Image source=Yonhap News]

A variable that could affect the accuracy of this general election's exit polls is the high early voting rate. Kim pointed out, "Early voters have come close to making up 50% of all voters, and how to reflect this early voting is the biggest challenge." He elaborated, "If the voting tendencies of early voters and those voting on election day are similar, there is no need to worry, but past elections have confirmed that their tendencies differ," adding, "Combining the predictions of early voting and election day voting is a major task."

Kim explained, "According to election law, exit polls cannot be conducted for early voting, so the results of early voters are confirmed through telephone surveys," and "These are combined with the exit polls of election day voters to calculate the final prediction for each electoral district."

Since its first implementation in 1995, the exit polls conducted by the three major broadcasters have shown high accuracy in predicting winners. In the first presidential election exit poll in 2002, the three broadcasters predicted the victory of candidate Roh Moo-hyun, and in 2007, 2012, and 2017, they correctly forecast the wins of Lee Myung-bak, Park Geun-hye, and Moon Jae-in, respectively. During the 2022 20th presidential election, the exit polls by the three broadcasters predicted candidate Yoon Seok-youl at 48.4% and candidate Lee Jae-myung at 47.8%, with the actual results being 48.6% and 47.8%, respectively.