Attitudes and measurement error revisited: a reply to Johnston and Pattie

Abstract

In a recent Note in this Journal, Johnston and Pattie 1 contend that they have discovered an ecological fallacy in the behaviour of the six-item scale 2 developed by Heath et al. to measure the ‘left-right’ political value dimension. 3 Using data from the first six waves of the British Household Panel Study (BHPS), they show that, while there is remarkable over-time stability in the factor structure of these questions at the aggregate level, when the consistency of individual responses to each item is considered, a very different picture emerges; around 50 per cent of the sample fail to select the same response alternative on successive waves and a third of respondents select a response alternative on the opposite side of the agree/disagree scale from one time to the next. Correlations between the same items over time of around 0.4, they argue, bear out a picture of massive longitudinal instability at the individual level