What Cognitive Interviews Reveal about Life Satisfaction Measurement

Life satisfaction is a key construct in research and policymaking on wellbeing. However, the use of life satisfaction data relies on strong assumptions, including 1) linear scale use, 2) interpersonal comparability, and 3) intertemporal comparability. Each of these depend on the shape of the reporting function: the process by which individuals convert latent life evaluations to numerical responses on a bounded scale. To understand the properties of this reporting function, we conducted theory-informed cognitive interviews with 100 residents of the United Kingdom and explored first-person accounts of life satisfaction scale use. While our results confirm previous psychometric validations of life satisfaction scales, we also find systematic violations of all three assumptions. For example, many respondents do not use the top of the scale, major shocks appear to alter the meaning of the points on the scale, and respondents rarely describe their own scale use as linear.