Damage, Living Environment, and Reconstruction Under the Great East Japan Earthquake-The 2nd Survey of Nuclear Disaster Evacuees from Futaba, Fukushima, Summary of Results 2014

2020年03月26日

（岩﨑 敬子） 保険会社経営

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1――Basic Information

Surveys on the damage, living environment and reconstruction under the Great East Japan Earthquake have been conducted via a research project called the "International comparison of reconstruction of living infrastructure from disasters" (Yasuyuki Sawada, Professor, Graduate School of Economics, The University of Tokyo; Keiko Iwasaki, Researcher, NLI Research Institute) of the University of Tokyo since 2013. The surveys target all household heads of Futaba in Fukushima prefecture, where all residents were forced to evacuate due to the nuclear power plant accident caused by the Great East Japan Earthquake that occurred in 2011. Surveys were conducted in July 2013, December 2014, July 2016, December 2017 and July 2019. This paper reports the summary of results of the second survey conducted in December 2014.1
The survey includes questions about basic attributes such as age and gender, as well as questions related to connections with others (social capital) and health conditions (see the appendix at the end of this report for all the questions included in the survey). The questionnaires were distributed to all households of Futaba (about 2,900 households) that receive the regular town mail from Futaba. We received responses from 654 Futaba residents who had evacuated nationwide (the response rate was about 23%).

The survey targeted heads of households and Figures 1 and 2 show the distribution of age and gender of the respondents. As we can see from these figures, compared to the age and gender distribution reported in the national census, the age distribution of the respondents is left-skewed, with the majority of respondents in their 60s. The gender distribution shows that the majority of respondents are male. In addition, since the survey was conducted after the tremendous disaster, it is possible that the distributions of the respondents' characteristics are significantly different from those of general questionnaire surveys. Therefore, it should be noted that the results of this survey do not necessarily indicate the general trend of Futaba residents.
 
1 This research was supported by the following research grants.
　Grant-in-Aid for Scientific Research (15 J09313, 26220502, LZ003), Research Grants of the Japan Center for Economic Research.
　This study is approved by the Ethics Committee of the University of Tokyo (19 -73).
 

2――Change in Social Capital

2――Change in Social Capital

Social capital refers to trusting relationships and networks, and is sometimes referred to as "kizuna" in Japanese. Social capital is getting attention as a key notion to achieve successful disaster recovery and has been one of the major focuses of our study. In previous studies, we found that social capital might have been weakened by the disaster among Futaba residents.

There are several indicators that are commonly used to measure social capital, but we focused on three items which are the level of "generalized trust", "frequency of mutual assistance with neighbors" and "trust in neighbors". As shown in Figure 3 to 5, all of these three indicators show that social capital has weakened because of the disaster and recovery trends cannot be observed so far. These indicate that it will take a very long time for social capital to recover, and we believe it is important to continue to monitor these changes over the long term.

3――Health Condition

3――Health Condition

We included a question asking changes in health condition compared to pre-disaster status. As shown in Figure 6, many respondents rated their own health condition as worse than that of their pre-disaster status and the distribution has hardly changed since 2013.
As for mental health, the distribution of K6 score, a clinically validated index for diagnosing the overall stress state, shown in Figure 7 indicates that K6 scores of Futaba residents are much higher compared to those for Japan. (K6 is an internationally used measurement for general mental health status that consists of six questions. The higher the total score, the more likely the respondent is stressed.)
K6 score distributions have been reported in disaster affected areas other than Futaba by the Government and local governments as well. As shown in Figure 8, K6 scores of Futaba residents tend to be higher than those of residents in other disaster affected areas, such as Wakabayashi area of Sendai and Ogatsu and Ojika area of Ishinomaki where the damages caused by the tsunami were tremendous. We believe that manmade disaster could have more serious and longterm impacts on victims’ mental health status because of their unique characteristics including uncertainty of the future.

However, the results of this survey do not necessarily apply to all residents of Futaba, and a high K6 score does not necessarily mean that one has a mental disorder. Please note that the purpose of our survey is to provide policy implications to the Government or other administrative agencies.

Moreover, we analyzed characteristics of those who chould keep good mental health under the tremendous disaster, and found that those who could keep good subjective health status after the disaster, those who have high income after the disaster and those who could keep high level of social capital tend to keep good mental health status after the disaster. As a mechanism connecting social capital and mental health, our study implied that high level of structural social capital helps people to have high level of cognitive social capital, which eventually helps people to keep good mental health (see Figure 9).
As shown in Figure 9, those who have many neighbors from Futaba and those who attend hobby gatherings tend to have high level of cognitive social capital, and also tend to have good mental health status.

In addition, as to changes in income, health status, and living space caused by the disaster, we find that the greater the extent of decrease or deterioration is, the greater the degree of decline in individual well-being tends to be.

These results have been presented at international and domestic academic conferences. In addition, these results have been published in international academic journals. We intend to continue our analysis and contribute to the improvement of disaster preparation/rehabilitation policies.

Our survey results are based on aggregates and analyses of responses from approximately 23% of the households of Futaba and do not represent all Futaba residents. Since the survey was conducted after a major disaster, the characteristics of respondents may be very different from general surveys and there is a possibility of an overestimation in our results due to the deterioration of physical and mental health conditions. Therefore, special caution is required in interpreting the results, and any definitive judgments based solely on these findings should be avoided.

【次ページ】Appendix: Summary Tables

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保険研究部   准主任研究員

岩﨑 敬子（いわさき けいこ）

研究領域：保険

研究・専門分野
応用ミクロ計量経済学・行動経済学　

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経歴 ＋ －

【職歴】
　2010年 株式会社 三井住友銀行
　2015年 独立行政法人日本学術振興会 特別研究員
　2018年 ニッセイ基礎研究所　研究員
　2021年7月より現職

【加入団体等】
　日本経済学会、行動経済学会、人間の安全保障学会
　博士（国際貢献、東京大学）
　2022年　東北学院大学非常勤講師
　2020年　茨城大学非常勤講師

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関連カテゴリ・レポート

基礎研レポート

ライフデザイン

人口動態

社会貢献・ボランティア

高齢者のQOL（生活の質）

健康・ヘルスケア