Are proxy interviews associated with biased earnings reports? Marital status and gender effects of proxy.

Social science findings routinely rely on proxy-reported economic data in household surveys. A typical assumption is that this information is not biased compared to self-reports, but empirical findings on the issue are mixed. Using a dataset that links workers in the 2004 Survey of Income and Program Participation to their W-2 tax records, we estimate the effects of reporting status (proxy vs. self) on the magnitude and direction of measurement bias in earnings data and explore whether these effects are heterogeneous across gender and marital status. A slight downward bias in proxy-reported earnings is observed; however, these effects are associated with demographic variables. For married workers, proxies do not contribute substantial bias in earnings measurement regardless of the target respondent's gender. However, for single female workers, proxy interviews are a significant source of downward bias in earnings estimates. The implications of these findings are discussed.