In this paper we use the U.S. Department of Agriculture's "Standard 6-Item Indicator Set for Classifying Households by Food-Security-Status Level." USDA and its contractors analyzed answers to 59 different food hardship questions included in the April food security supplement to the monthly CPS. USDA used the Rasch measurement model to validate a scale, ranging from "food secure" to "severe hunger," based on answers to 18 of these questions. USDA has released food hardship figures for 1995 through 1999, using this 18-item scale and CPS data. USDA also validated a 6-question scale for use in other surveys; this scale is shorter in order to reduce respondent burden. The 6-item scale does not included questions concerning more severe levels of hunger, and so it allows three possible determinations: "food security", "food insecurity without hunger", and "food insecurity with moderate hunger" (Bickel et al. 2001). The six questions are:
1. "The food that we bought just didn't last, and we didn't have money to get more." (Positive if this was often or sometimes true, negative is this was never true.)
2. "We couldn't afford to eat balanced meals." (Positive if this was often or sometimes true, negative if this was never true.)
3. In the last 12 months did you or other adults in your family ever cut the size of your meals or skip meals because there wasn't enough money or food? (Yes or no.)
4. (Ask only if yes on question 3.) How often did this happen--almost every month, some months, but not every month, or in only 1 or 2 months? (Positive if almost every month or some months, negative if in only 1 or 2 months.)
5. In the last 12 months, did you ever eat less than you felt you should because there wasn't enough money to buy food? (Yes or no.)
6. In the last 12 months were you ever hungry but didn't eat because you couldn't afford enough food? (Yes or no.)
Families providing zero or one positive response are considered "food secure." Those providing two, three, or four positive responses are "food insecure without hunger." And those with five or six positive responses are "food insecure with moderate hunger."
Following USDA guidelines, we imputed responses for missing values for the six food security questions, although item non-response was rare. If any question was not answered, and there was an affirmative answer on a question higher on the scale, but no negative answer lower on the scale, then an affirmative answer was imputed for that question. Otherwise, a negative answer was imputed. Fifty cases had no responses to all six food security questions, and they were coded as "food secure."