Electors not liable for jury service as a sampling frame for the elderly

Data from 449 persons aged over 65 who had been respondents to a population-based survey and 96 non-respondents aged over 65 were studied to compare those who had declared their age at electoral registration with those who had not. It was found that only 75% (79% of respondents and 57% of non-respondents) had declared their age. In an analysis of 16 variables among the respondents, a statistically significant difference for social class among males was found in that relatively fewer from Social Classes IV and V had declared their age. As an administrative instrument for estimating the size of the elderly population, the list of those marked as not liable for Jury Service on the electoral roll is clearly inadequate, giving an underestimate of about 25%. This could possibly be improved upon by better design of the electoral return form.