How reliable are income data collected with a single question

• Published in: Journal of the Royal Statistical Society. Series A, Statistics in society Vol. 173; no. 2; pp. 409 - 429
• Main Authors: Micklewright, John, Schnepf, Sylke V.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.04.2010; Blackwell Publishing Ltd; Blackwell Publishing; Blackwell; Royal Statistical Society; Oxford University Press
• Series: Journal of the Royal Statistical Society Series A
• Subjects: Age; Applications; Attitude surveys; Biology, psychology, social sciences; Children; Combinatorics; Combinatorics. Ordered structures; Comparative analysis; Data analysis; Data collection; Designs and configurations; Distribution; Exact sciences and technology; Family income; General topics; Gross income; Household income; Households; Income; Income data; Income distribution; Income estimates; Mathematics; Measurement; Men; Polls & surveys; Probability and statistics; Probability theory and stochastic processes; Quality; Questions; Reliability; Sciences and techniques of general use; Social survey; Social surveys; Special processes (renewal theory, markov renewal processes, semi-markov processes, statistical mechanics type models, applications); Statistical methods; Statistics; Survey design; Surveys; United Kingdom; United Kingdom > UK; Measurement; Data analysis; Covering problem; Social sciences; Household; Social survey; Non response; Life test; Sociometry; Industry; Statistical method; Income data; Survival analysis; Income distribution; Engineering; Quality; Distribution function; Reliability; Sample survey; Application
• ISSN: 0964-1998; 1467-985X
• DOI: 10.1111/j.1467-985X.2009.00632.x

Income is an important correlate for numerous phenomena in the social sciences. But many surveys collect data with just a single question covering all forms of income. This raises questions over the reliability of the data that are collected. Issues of reliability are heightened when individuals are asked about the household total rather than own income alone. We argue that the large literature on measuring incomes has not devoted enough attention to 'single-question' surveys. We investigate the reliability of single-question data by using the UK Office for National Statistics's Omnibus survey and the British Social Attitudes survey as examples. We compare the distributions of income in these surveys--individual income in the Omnibus and household income in the British Social Attitudes survey--with those in two larger UK surveys that measure income in much greater detail. Distributions compare less well for household income than for individual income. Disaggregation by gender proves fruitful in much of the analysis. We also establish levels of item non-response to the income question in single-question surveys from a wide range of countries.