| Japan | South Korea | Beijing | Hangzhou |
Study population | Over 20 years | Over 19 years | Over 18 years | Over 18 years |
Sample | 2-stage sampling | 3-stage sampling | 2-stage sampling | 2-stage sampling |
Survey mode | Face to face interview | |||
Target number of samples | 1800 | 1000 (quota) | 1000 (quota) | 1000 (quota) |
Completed interviews | 894 | 1002 | 1000 | 1011 |
Survey period | 2011/2/2-14 | 2011/1/13-2/14 | 2011/10/2-16 | 2011/10/13-25 |