Essay: Is the wealth index a proxy for consumption expenditure? A systematic review

• Published in: Journal of epidemiology and community health (1979) Vol. 63; no. 11; pp. 871 - 877
• Main Authors: Howe, L D, Hargreaves, J R, Gabrysch, S, Huttly, S R A
• Format: Journal Article
• Language: English
• Published: BMJ Publishing Group 01.11.2009
• Subjects: Consumer research; Consumer spending; Datasets; Economic indices; Household consumption; Poverty; Proxy reporting; Proxy statements; Socioeconomics; Wealth
• ISSN: 0143-005X

Background: Many epidemiological studies require a measure of socioeconomic position. The monetary measure preferred by economists is consumption expenditure; the wealth index has been proposed as a reliable, simple alternative to expenditure and is extensively used. Methods: A systematic review was conducted of the agreement between wealth indices and consumption expenditure, summarising the agreement and exploring factors affecting agreement. Results: Seventeen studies using 36 datasets met the inclusion criteria. Of these, 22 demonstrated weak agreement, 10 moderate agreement, and four strong agreement. There was some evidence that agreement is higher: in middle-income settings; in urban areas; for wealth indices with a greater number of indicators; and for wealth indices including a wider range of indicators. Conclusions: The wealth index is mostly a poor proxy for consumption expenditure.