§ Mr. John Mooreasked the Secretary of State for Social Services, further to his reply of 5th December, if he will publish in the Official Report the statistics of the 920W Registrar General that indicate that two or three persons out of 10 approached do not reply to a voluntary census; and whether he has considered combining a voluntary section with a compulsory section for the anticipated 1981 census.
§ Mr. EnnalsIn the test census held in April 1977, which was aimed at over 100.000 households, completed forms were received from 72 per cent. of households approached; it was not possible to contact 6 per cent. of households, and 22 per cent. refused to complete and return a form. In the earlier test censuses in 1972 and 1974, 78 per cent. of households approached completed a form. Similar results have been obtained in other voluntary surveys.
There is no way of testing a form that has both a compulsory and a voluntary section except in an actual census. I agree with the Registrar General that the presence of a voluntary section would lead to parts of the compulsory section being treated by some of the public as if they were voluntary. Moreover, a response rate of 70 to 80 per cent. would not provide acceptably reliable results for the questions asked in a census of population.