The committee examined evidence for the impact of various environmental factors on the feasibility of defining the adequacy of SNAP allotments. The range of available evidence included specific environmental factors affecting food choices: food prices; access to food outlets offering a wide range of healthy foods; and disparities in access, particularly in transportation. The committee notes that relevant data collection is ongoing but the data are not yet available through the ERS National Household Food Acquisition and Purchase Survey. When completed, this survey will provide detailed information on household food purchases and acquisitions, including foods purchased for consumption at and away from home and foods acquired through public and private food and nutrition assistance programs. This dataset will be useful for a broad range of economic analyses of food choices and for understanding the implications of food choices for diet quality.
Access to food varies substantially across households because of the various factors affecting food prices. These factors include a number of environmental dimensions, such as geographic region of the country; urban versus rural setting; types of stores available (e.g., supermarkets, convenience stores, mass merchandisers, warehouse club stores); and types of foods available, such as healthier versus less healthy and degree of processing (e.g., raw ingredients, processed ingredients, processed foods, fully prepared foods). Over time, food prices are influenced by changes in costs, due largely to inflationary factors, for farm-level inputs and production, transportation at each stage of production, food processing, and food distribution, which may result in greater or lesser changes than in overall prices for all goods and services. Considering food prices as a component of the evidence needed to define the adequacy of SNAP allotments is important because the influence of food prices on the likelihood of food insecurity is both positive and significant; an increase of one standard deviation in the price of a food basket based on the TFP results in increases in food insecurity of 2.4 percentage points for adults and 3.7 percentage points for children (Gregory and Coleman-Jensen, 2011). In the following discussion, the committee describes the differences in food prices across several dimensions and changes in food prices over time in the context of how these patterns affect food access as a factor in defining the adequacy of SNAP allotments.