We investigate how monthly household income volatility and income shocks affect food assistance receipt among low-income U.S. households since 1990, with a particular focus on possible differences by geographic region, urban/rural residence, race, and ethnicity.  Previous related research raises issues of considerable importance for food assistance:  Rising monthly income volatility leads to increasing food hardship, however if food assistance certification and recertification procedures rely on documentation of monthly household income over multi-month periods, the availability of assistance may be insufficiently responsive to the periods of short-term income instability that households suffer.  These implications of income volatility are relatively unstudied and poorly understood. 

This research fills this gap.  We use records on U.S. households from the 1991, 1992, 2001 and 2008 panels of the Survey of Income and Program Participation (SIPP) to measure changes in the degree of household income instability over time and how this relates to food assistance receipt, as well as to a variety of measures of food and material hardship.  This analysis spans the years 1991-93, 2002-03 and 2008-11, illuminating our understanding of these issues over a 20-year period of significant economic events and policy developments.  In addition, we use the results of this analysis to examine how the food assistance status of households experiencing varying levels of income volatility would change under various prototypical food assistance certification regimes common across states.