Institute of Political Science at Academia Sinica Technical Report for Asian Barometer Survey Japan wave4 July 21, 2016 Central Research Services, Inc. 1
[RESEARCH DESIGN] <Outline> - Research Method: Face to Face Interview - Survey Type: Ad-hoc survey - Sampling Method: Two stage stratified sampling - Research Region: Nationwide - Research Target: Representative national sample (individuals age 20 and older) - Sample size: 2,500 [Sample Design] - Sample Universe: National population in Japan above age 20 (based on Basic Resident Resister (jyu-min kihon daichou) as of January 2015) - Sampling Method: Two stage stratified random sampling method was employed in order to ensure random selection of individual respondents. Therefore, the completed interviews combined, would be a reduced copy of the national population above age 20, thus representing the public opinion. The Primary Sampling Unit (PSU) was the census unit from the Statistics Bureau (Census report). The Secondary sampling unit (SSU) was individual. By reviewing Basic Resident Resister which was provided by each local government, respondents were selected randomly with calculated interval. - Definition and Number of PSU and SSU and Sampling Points: * PSU: For each stratum, we selected PSU from census units in Japan by using systematic sampling and sampling intervals. * SSU: The sampling unit for the second stage was individual. Using Basic Residential Resister, respondents within each PSU were randomly selected. *Sampling Points: 210 - Stratification: Two stage stratified sampling 12 regions * 5 City Size As for the first step of our stratification process, we divided the nation into 12 groups (1:Hokkaido, 2:Tohoku, 3:Kanto, 4:Keihin 5:Hokuriku, 6:Tozan, 7:Tokai, 8:Kinki, 9:Chugoku, 10:Shikoku, 11:North-Kyusyu, and 12:South-Kyusyu). Each area was stratified by its population size. (Size1: 20 government ordinance-designed major cities plus the 23 Tokyo Wards, Size2: Cities with more than 200,000 population, Size3: Cities with more than 100,000 population, Size4: Other cities, Size5: Rural areas). 2
(Chart 1: Geographical Stratification) Region City size 1 2 3 4 5 6 7 8 9 Total City with City with City disignated 200,000+ 100,000+ Other city by ordinance population population Rural 01 1617980 522595 741756 811503 849408 4543242 Hokkaido 39(3) 13(1) 18(2) 19(2) 20(2) 109(10) Sapporo 02 856933 1925146 889903 2452389 1433351 7557722 Tohoku 21(2) 46(4) 21(2) 59(5) 34(3) 181(16) Sendai 03 772256 1012269 580140 8067728 6354878 4846711 1604793 23238775 Kanto 19(2) 24(2) 14(1) 194(14) 153(11) 117(9) 39(3) 560(42) Chiba Saitama Sagamihara 04 7432939 3002314 1165178 11600431 Keihin 179(13) 72(6) 28(2) Tokyo 23 waryokohama Kawasaki 279(21) 05 662239 1149937 653248 1584907 354916 4405247 Hokuriku 16(2) 28(2) 16(2) 38(3) 9(1) 107(10) Niigata 06 838666 707577 1827752 724304 4098299 Tozan 20(2) 17(2) 44(4) 17(2) 98(10) 07 1812819 587619 643801 2151983 2467821 2087421 696548 10448012 Tokai 44(4) 14(1) 15(2) 52(4) 59(5) 50(4) 17(2) 251(22) Nagoya Shizuoka Hamamatu 08 2144786 1150045 1245455 680071 4970741 2382910 3271697 973111 16818816 kinki 52(4) 28(2) 30(3) 16(2) 120(9) 57(5) 79(6) 23(2) 405(33) Osaka Kyoto Kobe Sakai 09 946577 562720 1350055 1490142 1269528 492008 6111030 Chugoku 23(2) 13(1) 32(3) 36(3) 31(3) 12(1) 147(13) Hiroshima Okayama 10 1253534 419897 1051259 533213 3257903 Shikoku 30(3) 10(1) 25(2) 13(1) 78(7) 11 795947 1188002 1388280 690901 2049170 819699 6931999 North-Kyusyu 19(2) 29(3) 33(3) 17(2) 49(4) 20(2) 167(16) Kitakyusyu Fukuoka 12 587930 1066794 815632 1542766 863480 4876602 South-Kyusyu 0(0) 26(2) 34(3) 37(3) 21(2) 118(10) Kumamoto Total Population 9577725 6761125 7792381 1599888 3716901 24685459 17614665 22795103 9344831 103888078 Sample size(sampling point) 231(17) 163(14) 189(17) 38(3) 74(8) 594(47) 438(38) 548(45) 225(21) 2500(210) 3
(Chart2: Prefectures and cities/wards in 12 regions) Region Prefecture 01 Hokkaido Hokkaido Aomori Iwate 02 Tohoku Miyagi Akita Yamagata Fukushima Ibaraki Tochigi Gumma 03 Kanto Saitama Chiba Tokyo Kanagawa Tokyo 04 Keihin Kanagawa 05 Hokuriku 06 Tozan 07 Tokai 08 Kinki 09 Chugoku 10 Shikoku 11 12 North Kyushu South Kyushu Kanagawa Niigata Toyama Ishikawa Fukui Yamanashi Nagano Gifu Shizuoka Aichi Mie Shiga Kyoto Osaka Hyogo Nara Wakayama Tottori Shimane Okayama Hiroshima Yamaguchi Tokushima Kagawa Ehime Kochi Fukuoka Saga Nagasaki Oita Kumamoto Miyazaki Kagoshima Okinawa City excluding Keihin region excluding Keihin region Tokyo 23 wards Yokohama Kawasaki 4
[Fieldwork Procedure] - Selection and Training of Interviewers: All interviewers participating in this project were registered interviewers for CRS. As of March 2016, CRS has approximately 790 registered interviewers who are selected based on the following criteria. (a) Experience in more than 10 face to face interviews (b) Completed more than 100 samples (c) High response rates, effectiveness in the field, quality of completed interviews (d) Capable of continuing the task on a regular basis An average CRS registered interviewer has 13.1 years of field experience. They are required to take a 5-hour fieldwork training session once a year to learn fieldwork techniques and review the privacy laws. Apart from the training session, they also receive regular advice from their local supervisor for each assigned project. In order to maintain a good relationship and hear opinions from the interviewers, informal gatherings are held periodically in each local branch. Feedback and comments from the interviewers to improve fieldwork situation are recorded by local supervisors and sent to the main office in Tokyo for review. There is a commendation system for interviewers with outstanding performance. This contributes in maintaining their motivation and performance. - Number of interviewers assigned to this project: 210 - Number of supervisors assigned to this project: 55 5
(Chart3: CRS Branches and number of registered interviewers) Branch Number of Number of supervisors interviewers Prefecture in charge Tokyo 3 200 Tokyo, Kanagawa, Chiba, Saitama Chiba 1 11 Chiba Saitama 1 31 Saitama Maebashi 1 8 Gunma Utsunomiya 1 11 Tochigi Mito 1 11 Ibaraki Koufu 1 5 Yamanashi Nagano 1 12 Nagano Niigata 1 16 Niigata Sapporo 1 10 Hokkaido Obihiro 1 9 Hokkaido Kushiro 1 4 Hokkaido Asahikawa 1 10 Hokkaido Hakodate 1 7 Hokkaido Tomakomai 1 4 Hokkaido Sendai 1 16 Miyagi Aomori 1 3 Aomori Akita 1 7 Akita Morioka 1 5 Iwate Yamagata 1 4 Yamagata Fukushima 1 14 Fukushima Hachinohe 1 2 Aomori Nagoya 1 43 Aichi Shizuoka 1 14 Shizuoka Hamamatsu 1 12 Shizuoka Gifu 1 14 Gifu Tsu 1 6 Mie Toyama 1 7 Toyama Kanazawa 1 7 Ishikawa Fukui 1 10 Fukui Osaka 3 50 Osaka Kyoto 1 12 Kyoto Kobe 1 10 Hyogo Himeji 1 6 Hyogo Otsu 1 13 Shiga Nara 1 9 Nara Wakayama 1 7 Wakayama Hiroshima 1 18 Hiroshima Okayama 1 7 Okayama Tottori 1 8 Tottori Matsue 1 10 Shimane Yamaguchi 1 6 Yamaguchi Shimonoseki 1 1 Yamaguchi Matsuyama 1 7 Ehime Takamatsu 1 7 Kagawa Tokushima 1 7 Tokushima Kouchi 1 1 Kochi Fukuoka 1 19 Fukuoka Kitakyusyu 1 9 Fukuoka Saga 1 6 Saga Nagasaki 1 3 Nagasaki Kumamoto 1 9 Kumamoto Oita 1 10 Oita Miyazaki 1 6 Miyazaki Kagoshima 1 6 Kagoshima Naha 1 9 Okinawa 6
- Interview method: Face to Face The survey adopted a face to face interviewing method (in-person). Interviewers visited the household of respondent and conducted the interview to the person who was randomly selected before the survey if he/she agreed to cooperate. If the respondent was willing to be interviewed, the interviewer handed the show-cards to the respondent and read out the questionnaire one by one in front of him/her. The respondent chose answer(s) from the list on the show-cards which the interviewer recorded on the questionnaire. Upon completing the interview, the interviewer gave the respondent their incentive, which was a book coupon (1,000 Japanese Yen). - Methods for ensuring quality control in the field: All registered interviewers are given The Handbook for Interviewing. In the handbook, basic instructions and techniques for conducting a face to face interview are written. Apart from the handbook, an instruction manual specifically for this project was also provided to the interviewers. Prior to the fieldwork, all interviewers assigned to the project were required to attend an instruction session held in the local CRS branch. At the session, supervisors reviewed the manual with the interviewers and checked that they understood the aim and purpose of the project. If any problem or question arose during any point of the fieldwork, interviewers contacted their local supervisor or staffs in the main office as soon as possible and to sought advice. [Data Entry and Management] ASCII format. All data were entered into an SPSS data file (file extension.sav) and also saved in - Data Cleaning and Verification: All collected data went through two steps; (1) an online check program and (2) data verification by our staff, to ensure its validity and to produce a clean data. (1) Online Check: The purpose of this process is to confirm the accuracy of the data by conducting a logical check. In our check program, we detected below cases as a logical error. Such data were picked out and checked with the original questionnaire. 7
[Cases of logical error] (a) Duplication of ID number (b) Multiple answers for single answer question (c) Entry of code number that does not apply to the question (d) Answers to sub-questions in which the respondent does not fall under the category (e) Inconsistent answers to demographic questions (f) Abnormal figures for questions requiring numerical values (g) Contradicting answers between questions (2) Data verification by staff: After all the data went through an online check, an error list showing data containing logical error were produced. Our staff then examined both the error list and the original questionnaire for each error and corrected it accordingly. The correction was recorded both in the error list and the original questionnaire in red for future reference. Process (1) and (2) described above were repeated until no logical error appeared on our check program. All deliverables (marginal frequencies and raw data) were produced based on the data which went through the above data cleaning procedures. [Deliverables] * Marginal Frequencies * Raw Data (SPSS data file) [Sampling Performance] Number of completed interviews: 1,081 8