The analysis of the long-term effect of lowering of voting age from 18 to 20 among Japanese young people

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K01428
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 06010:Politics-related
• Research Institution: Kwansei Gakuin University
• Principal Investigator: ZENKYO Masahiro 関西学院大学, 法学部, 教授 (50625085)
• Co-Investigator(Kenkyū-buntansha): 秦 正樹 京都府立大学, 公共政策学部, 准教授 (10792567)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 若年層 / 政治関心 / 投票選択 / 選挙権年齢 / 引き下げ / 回帰非連続デザイン / コンジョイント実験

Outline of Final Research Achievements

This study examines the causal effect of lowering the voting age from 20 to 18 on political attitudes and elucidates the political decision process of young people in Japan. For these purposes, we conducted two original online survey for Japanese young people in 2019 and 2020. The findings of the empirical analysis are as follows. First, the long-term effects of lowering the voting age on political attitudes such as political interest were null, and the short-term effects were also not statistically significant. Second, this study finds that Japanese young people tend to use visual cues when they choose candidates in elections. Results of the conjoint survey experiment show that the causal effect of “smile” on voting choice was statistically significant. However, at the same time, we also found that participants were less likely to rely on the "smile" cues when the candidates’ policy stances are clear.

Free Research Field

政治学

Academic Significance and Societal Importance of the Research Achievements

本研究の学術的意義は第1に、選挙権年齢引き下げの効果を、短期的影響だけではなく中長期的影響まで視野に入れつつ、明らかにしたことである。加えて第2に、視覚的手がかり(cues)が用いられる条件を、若年層を対象とするコンジョイント実験を通じて解明したことである。これら本研究の知見は、選挙権年齢引き下げの成果について一定の示唆を与えるものとなっている。本研究の知見は、18歳という早い段階であっても、投票への参加機会を設けるだけで若年層の政治関心は向上しないことを明確に示す。若年層の低投票率問題を解決するには、関与機会の提供以上の工夫が必要である。