[ 중앙일보 ] 2012 - 12 - 27 The flawed math of Moon Jae - in / Karl Friedhoff , 아산 정책 연구원 여론 연구 센터 연구원 The so - called “ Moon surge ” in the last week before the presidential election received plentiful media coverage with some predicting a Moon victory based on that surge just days before the election . There was just one problem – that surge never took place . Instead , the perceived strengthening of Moon Jae - in was the product of media hype , a misunderstanding of public opinion polls , and his ultimate loss was due in part to his own camp ’ s fundamental misunderstanding on how voter turnout works . 
 While it is true that Moon Jae - in had an impressive rise from August through December – rising from support of just 10 percent to seriously challenge Park Geun - hye – in the last two weeks before the election there was no evidence of a surge for Mr . Moon in the polls . For every poll conducted by Research & Research after Dec . 3 , support for the two candidates was within the margin of error . Moreover , in the last six days of the campaign – during which time polling results were embargoed due to Korean election law – that spread was consistently narrower than 2 percentage points . Thus , any perceived gains by Mr . Moon during that time could just as well have been the result of the random sampling error which is a part of any poll . Thus , Moon ’ s rise was certainly a good story , added intrigue to the election , and it almost certainly sold newspapers . But the Moon surge was a case of the media getting caught in its own echo chamber . 
 The most likely explanation is that when thresholds for a Moon victory were calculated , turnout for those in their 50 s and 60 s were held at a near constant to their historical trends . In presidential elections since 2002 , that turnout has been approximately 78 percent . Thus , by holding that turnout constant , calculations were then made on what kind of turnout would be required of those in their 20 s and 30 s to swing the election in Moon ’ s favor . However , the core assumption of that model did not hold because when voter turnout increases it almost always increases across all age cohorts , not only among certain age cohorts . While the turnout among voters in their 20 s reached 65 percent – 13 percentage points higher than the previous two presidential elections – the turnout among those in their 50 s reached a staggering 90 percent . Among all the focus on the youth vote , analysts forgot that old voters could also be galvanized , and this is where increased media attention can be a double - edged sword . The steady reports of a Moon surge may have galvanized older voters – voters who overwhelmingly support Park Geun - hye – as well . It was precisely that galvanization that won the election . These assumptions on voter turnout bring the demographics of Korea into sharp relief , and those demographics never favored Moon Jae - in . While this story has only emerged in the media after the election , it went largely uncovered in the lead - up to the election . This was a serious oversight . Korea is an aging society , and since 2007 there has been a 4 . 6 percentage - point decline in the proportion of 20 s and 30 s in the total Korean electorate . Accordingly , there has been a 5 . 0 percentage - point increase among the proportion of voters in their 50 s and 60 s . As is well - established , they overwhelmingly supported Park Geun - Hye , and this trend is going to accelerate . Their increased numbers , along with their historically higher turnout , made the path to victory for Moon Jae - in an improbable one . As the Korean population ages , the leading progressive party – in whatever name or form it takes for the next election – will need to focus on addressing the increasingly complex positions of older voters . The flawed assumption on voter turnout led the Moon campaign to over - focus on getting out the youth vote rather than addressing these complex concerns and gaining support among Park ’ s base . In the coming elections , these older age cohorts will hold the key to victory , and if the progressive political parties fail to understand that they can look forward to the kind of disappointments they had in 2012 . Simply getting out the youth vote was not , and will not be , a reliable path to victory .