Causal study on the effect of survey methods in the 19th presidential election telephone survey

19대 대선 전화조사에서 조사방법 효과에 대한 인과연구

  • Kim, Ji-Hyun (Department of Statistics and Actuarial Science, Soongsil University) ;
  • Jung, Hyojae (Department of Statistics and Actuarial Science, Soongsil University)
  • 김지현 (숭실대학교 정보통계보험수리학과) ;
  • 정효재 (숭실대학교 정보통계보험수리학과)
  • Received : 2017.09.28
  • Accepted : 2017.12.07
  • Published : 2017.12.31


We investigate and estimate the causal effect of the survey methods in telephone surveys for the 19th presidential election. For this causal study, we draw a causal graph that represents the causal relationship between variables. Then we decide which variables should be included in the model and which variables should not be. We explain why the research agency is a should-be variable and the response rate is a shouldnot-be variable. The effect of ARS can not be estimated due to data limitations. We have found that there is no significant difference in the effect of the proportion of cell phone survey if it is less than about 90 percent. But the support rate for Moon Jae-in gets higher if the survey is performed only by cell phones.

전화를 이용한 19대 대선 선거예측조사에서 ARS 조사비율과 무선전화 조사비율을 달리함에 따라 조사결과가 어떻게 달라지는가를 보았다. 조사방법이 조사결과에 미치는 효과를 추정하는 인과연구를 시도하였으며, 이를 위해 변수들 사이의 인과관계를 가정하는 인과 그래프를 그린 다음 모형에 포함시켜야 할 변수와 포함시키면 안 되는 변수를 판단하였다. 조사를 실시한 조사기관은 중첩변수로서 모형에 포함시켜야 하는 변수이며 응답률은 모형에 포함시키면 안 되는 변수임을 설명하였다. ARS 조사비율의 효과는 자료 한계 때문에 추정할 수 없었으며, 무선전화 조사비율이 약 90%를 넘지 않으면 효과에 별 차이가 없으나 전체 조사를 무선전화로만 실시하면 문재인후보지지율이 높아진다.



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