About the fourth wave of the survey(KHPS2007)

The fourth wave of the survey was implemented in the following manner.

- Day for the Survey
  The survey was implemented on 31 January 2007.

- Subjects for the Survey
  The 2,894 individuals who were subjects of the KHPS third wave
  (valid respondent 2,887 individuals and 7 individuals who did not respond KHPS the third wave,
but who indicate a wish to cooperate the survey.)

- Survey Method
  The survey was implemented by the drop-off pick-up (DOPU) method

- Types of Questionnaires
  Two types of questionnaires that differed according to whether there was a spouse or not were used.
And another questionnaire for spouse who married with respondent in the past year.

- Collection Rate
  Of 2,887 individuals who were surveyed, 2,640 individuals responded the survey, and then the collection rate was 91.4%.

  KHPS Fourth Wave Responses

Number of samples 2,894
Completed 2,643
Of which last respondent 2,640
Of which revival 3
Recovery rate 91.4%
Married 2,013
Single 630
Newlywed 16
Dropout 251

  Recovery rate (= ( (Completed-Revival ) / Completed in last year )×100)

The fourth wave of the survey was implemented in the following manner (New Cohort).

- Coverage of the Survey
  Males and females aged between 20 and 69 years as of 31 January 2007.
  (Males and females born between February 1938 and January 1988).
  According to the population estimates for March 2006, this population was about 84.71 million or 66.8% of the total population.

- Day for the Survey
  The survey was implemented on 31 January 2007.

- Choice of the Survey Subjects
(1)Sample Size
1,400 People (However, the files contained in the CD-ROM contain data on 1,419 individuals of whom 19 individuals were backups)
(2)Method for Obtaining Sample
Two stage stratified sampling (first stage was the survey area, and the second stage was the individual)
(3)Choice of Survey areas.
Census enumeration districts for the 2000 National Census were used as the survey areas.
First, the nation as a whole was stratified into 26 strata according to region and city size, for each stratum
the sample size was determined by the stratum’s population share of National Residents Register’s population as of 31 March 2005.
Next, based on a sample of about 5 for each sampling area, the number of sampling areas in each stratum was determined,
and the required number of survey areas were chosen at random for each stratum.

Details of the allocation of the sample across regions and city size are as follows

   16 Large Cities Other Cities Towns and VillagesTotal
Hokkaido 22 29 1263
Tohoku 11 70 20101
Kanto 179 267 27473
Chubu 32 193 29254
Kinki 70 146 14230
Chugoku 13 61 781
Shikoku  -  36 743
Kyushu 26 104 25155
Total 353 906 1411,400

(4)Choice of Survey Respondents
Survey respondents The National Residents Register or the Electoral Roll for the chosen survey area was used as the sampling register,
Limiting the sample to eligible individuals, and based on designated numbers and sampling interval for the survey area about 5 individuals were sampled.
However, when the sequencing of the sampling register did not follow the area sequencing or was not ordered according to
the Japanese alphabet within an area, using a map for residences every third residence was sampled within the required area.
(5)Choice of the back-up Sample
For this sample, in order to obtain a sample of 1,400 individuals, when an individual originally chosen for survey did not
take part in the survey,he or she was replaced by a person from the back up sample that had been previously determined.
The back up sample was chosen to have the same sex (male or female), the same age grouping
(in their 20s, in their 30s, in their 40s, in their 50s, in their 60s) as the original individual.


4th wave(KHPS2007) questionnaire PDF