Measurement of income in surveys


FORS Guide Nº 02

How to cite

Kuhn, U. (2019). How to measure income. FORS Guide No. 02, Version 1.0. Lausanne: Swiss Centre of Expertise in the Social Sciences FORS. doi:10.24449/FG-2019-00002


This guide is intended for survey designers who want to collect information on income. It addresses the main decisions that have to be taken for the questionnaire design, gives an overview of the implementation of the concept in current Swiss surveys and points out particularities in Switzerland.


  • When designing income questions, think carefully about how the income variable will be used, what kind of income you want to measure, how much questionnaire time you want to devote to income questions and evaluate if respondents will be able to deliver the correct information.
  • You should rather measure income with one summary question instead of multiple questions about income components, if you need information about the income only for classificatory purpose (e.g. social status). Only if the income is your main variable of interest, a more detailed measurement is required.
  • Consider the advantages, disadvantages and the implications regarding survey design and data quality, when you decide whether to measure personal or household income; gross, net or disposable income on a monthly or annual basis.
  • Check existing questionnaires and data on income to design your questions and eventually validate or situate your results.
  • Remember to collect information on household size to be able to compute equivalised income.


Copyright: © the authors 2019. This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0)