Family Resources Survey 2001-02
Survey non-response
The lower the response rate to a survey, the greater the likelihood that those who responded are significantly unlike those who did not, and so the greater the risk of systematic bias in the survey results. Unless information is available about the nature and extent of such bias there are likely to be problems in generalising the sample results to the population. For a British survey of the size and complexity of the FRS, the total non-response rate in 2001-02 of 34 per cent is not considered unreasonable. However, any information that can be obtained about the non-responders is useful both in terms of future attempts to improve the overall response rate and also potentially in improving the weighting of the sample results. It is considered a priority issue for the FRS to obtain as much information as possible about non-responders. The following sections outline some of the analysis that has been carried out in this direction.
FRS non-response and ACORN classifications
A number of household characteristics are often associated with a higher or lower response rate on surveys 
. Lower response rates than the average are often seen in:
- households in inner-city areas (especially London);
- single person households;
- head of household born outside the UK
In contrast, higher response rates occur, for example, in households with dependent children. A greater understanding of how these varied characteristics interact and influence survey response can be useful for weighting of results and for maximising response rates in the future.
A study based on 1995-96 and 1996-97 data compared response rates in relation to the ACORN code of a household. ACORN is a geo-demographic classification system developed by CACI Marketing Systems which classifies areas into 54 types, using Census data items such as age, sex, marital status, occupation, education, home ownership, car ownership, family structure and ethnic group. This suggested that wealthier households are less likely to respond to the survey than poorer households, but none of the 54 types had response rates more than 10% from the average.
In the analysis of non-response for 2001-02 , further work was undertaken to compare ACORN categories for respondents and non-respondents according to six broad groups. It was found that the distribution of respondent and non-respondent households across the six groups was broadly similar.
FRS non-response and Council Tax band
Comparisons were made between 2001-02 FRS data and administrative data on the number of households within each Council Tax band. Table M.3 
shows that FRS proportions were similar to those obtained from examining administrative data.
Non-response form analysis
Direct information about the non-responding households is valuable, although by definition difficult to obtain. However some households who are not willing to take part in the full survey may be willing to provide some basic information by completing a non-response form.
In 2001-02, 79% of households that refused to take part in the full survey answered questions from the non-response form . In addition, interviewers filled in a short questionnaire on all refusing and non-contactable households, based on observation or on information gleaned from neighbours. Key findings were:
- non-responding households were more likely to live in flats or maisonettes than respondents and less likely to live in houses or bungalows;
- refusing households were less likely than responding households to contain three or more adults and more likely to contain one or two adults. Refusing households were less likely to contain any children;
- refusing households were also less likely than responding households to contain members aged between 16 and 59;
- non-responding households were slightly less likely to have an Asian or Chinese or other ethnic group family member and slightly more likely to have a Black family member, but the differences are less than 1 per cent in all cases;
- refusing households were significantly more likely than responding households to have at least one member working.
