What is the best way to eliminate non-response bias?
It is almost impossible to eliminate it completely. The realistic goal is to minimize its impact. This is done primarily through the design of the survey. Research shows that people respond more frequently when: a) The questionnaire is clear, easy to follow, and short. b) Confidentiality is promised and kept. c) The questionnaire begins with a statement of purpose and convinces people that filling it out will benefit research or society. d) Incentives are given to respond (e.g., respondents enter in a lottery to win a prize; coupons, payments, or gifts are promised to respondents). e) Mailings don’t look like junk mail. There is an enormous research literature on avoiding nonresponse. By no means have we found the answer. This is a very active research area for statisticians, cognitive psychologists, and sociologists. In fact, if any one is interested in pursuing research in this area, let me know. There are some great summer internships available.
