Since the 1996 Panel of the Survey of Income and Program Participation (SIPP), information on work-related expenses has been collected through a series of questions contained in annual topical modules. This information is used to subtract a fixed amount from the incomes of all workers to account for work-related expenses when producing estimates of the Supplemental Poverty Measure (SPM). The 2014 Panel of the SIPP reflects the culmination of a reengineering process designed to reduce costs and improve data quality and timeliness. As part of this major survey redesign, changes to the interview reference period, core content, and reporting methods constitute a significant break in series for the work-related expense variables.

Given that the current method of calculating the fixed deduction used in the SPM is no longer appropriate due to changes in data collection, this research evaluates alternate methodologies to calculate the work-related expense deduction when using data from the 2014 and later SIPP Panels. Among proposed methods, preliminary unweighted estimates of work-related expenses in the 2014 SIPP, referencing calendar year 2013, are compared to unweighted estimates calculated from the 2008 SIPP Panel, which provided data for calendar years 2009, 2010 and 2011. Given that estimates are unweighted, this research is limited to evaluating observed differences across unweighted estimates and discusses the anticipated impact on poverty measures for the working-age population.

Differences in estimates of work-related expenses across the 2008 and 2014 SIPP Panels vary depending on the methodology used, although regardless of method, preliminary unweighted estimates indicate that work-related expenses increased from calendar year 2011 in the 2008 SIPP Panel to calendar year 2013 in the 2014 SIPP Panel. Preliminary estimates from the 2014 SIPP suggests increases stem from greater reported miles driven to and from work, as well as an increase in the percentage of workers reporting costs associated with miscellaneous expenses such as licenses, union dues or uniforms.