Food Insecurity and Hunger in the United States: An Assessment of the Measure (download the full report)
An assessment of USDA's food security measurement and monitoring methods by the Committee on National Statistics (CNSTAT), an arm of the National Research Council (a body of the National Academies) concluded that food insecurity and hunger are important to measure, that the current measurement of food insecurity should be continued, but that consideration should be given to strengthening the measure in several ways and that a different methodology for measuring hunger should be developed. The report is the product of an extensive review by an independent expert panel. USDA requested the Committee on National Statistics to convene this panel in the interest of ensuring that USDA's data collection and methodology in the areas of food security and hunger are relevant and scientifically sound.
What Are the Issues?
To inform policymakers and the public about the extent to which U.S. households consistently have economic access to enough food, ERS publishes an annual statistical report on household food security in the United States (see Readings for the annual report and a list of related reports). The reports are based on data collected in a national food security survey conducted as an annual supplement to the Census Bureau's Current Population Survey. The food security reports and the underlying data are widely used by government agencies, the media, and advocacy groups to report the extent of food insecurity in the U.S., to monitor the progress toward national objectives, and to monitor the performance of USDA's food assistance programs.
The terms "household food security," "food insecurity," and "food insecurity with hunger," which are used to describe households' access--or lack of access--to adequate food, are relatively new to both policymakers and the public. Concerns have arisen about whether USDA's concepts and measurement of food insecurity and hunger are appropriate for the policy contexts in which they are used.
How Was the Study Conducted?
ERS, in partnership with the Food and Nutrition Service (FNS), the agency that administers USDA's food assistance programs, asked the Committee on National Statistics to convene an expert panel to examine the concepts and methodology for measuring food insecurity and hunger and the uses of those measures. Specific uses include monitoring food security conditions, assessing the performance of food assistance programs, and conducting related research. The panel was made up of economists, sociologists, nutritionists, and other researchers. This report presents findings of the panel and recommendations to USDA to improve and strengthen the measure.
What Did the Study Find?
Following are the recommendations as summarized in the report:
Concepts and Definitions
Recommendation 3-1: USDA should continue to measure and monitor food insecurity regularly in a household survey. Given that hunger is a separate concept from food insecurity, USDA should undertake a program to measure hunger, which is an important potential consequence of food insecurity.
Recommendation 3-2: To measure hunger, which is an individual and not a household construct, USDA should develop measures for individuals on the basis of a structured research program, and develop and implement a modified or new data gathering mechanism. The first step should be to develop an operationally feasible concept and definition of hunger.
Recommendation 3-3: USDA should examine in its research program ways to measure other potential, closely linked, consequences of food insecurity, in addition to hunger, such as feelings of deprivation and alienation, distress, and adverse family and social interaction.
Recommendation 3-4: USDA should examine alternate labels to convey the severity of food insecurity without the problems inherent in the current labels. Furthermore, USDA should explicitly state in its annual reports that the data presented in the report are estimates of prevalence of household food insecurity and not prevalence of hunger among individuals.
Recommendation 4-1: USDA should determine the best way to measure frequency and duration of household food insecurity. Any revised or additional measures should be appropriately tested before implementing them in the Household Food Security Survey Module.
Recommendation 4-2: USDA should revise the wording and ordering of the questions in the Household Food Security Survey Module. Examples of possible revisions that should be considered include improvements in the consistent treatment of reference periods, reference units, and response options across questions. The revised questions should reflect modern cognitive questionnaire design principles and new data collection technology and should be tested prior to implementation.
Item Response Theory and Food Insecurity
Recommendation 5-1: USDA should consider more flexible alternatives to the dichotomous Rasch model, the latent variable model that underlies the current food insecurity classification scheme. The alternatives should reflect the types of data collected in the Food Security Supplement. Alternative models that should be formally compared include:
- Modeling ordered polytomous item responses by ordered polytomous rather than dichotomized item response functions.
- Treating items with frequency follow-up questions appropriately, for example, as a single ordered polytomous item rather than as two independent questions.
- Allowing the item discrimination parameters to differ from item to item when indicated by relevant data.
Recommendation 5-2: USDA should undertake the following additional analyses in the development of the underlying latent variable model:
- Fitting models that allow for different latent distributions for households with children and those without children and possibly other subgroups of respondents.
- Fitting models that allow for different item parameters for households with and without children for the questions that are appropriate for all households in order to study the possibility and effects of differential item functioning.
- Studying the stability of the measurement system over time, possibly using the methods of differential item functioning.
Recommendation 5-3: To implement the underlying latent variable model that results from the recommended research, USDA should develop a new classification system that reflects the measurement error inherent in latent variable models. This can be accomplished by classifying households probabilistically along the latent scale, as opposed to the current practice of deterministically using the observed number of affirmations. Furthermore, the new classification system should be more closely tied to the content and location of food insecurity items along the latent scale.
Recommendation 5-4: USDA should study the differences between the current classification system and the new system, possibly leading to a simple approximation to the new classification system for use in surveys and field studies.
Recommendation 5-5: USDA should consider collecting data on the duration of spells of food insecurity in addition to the currently measured intensity and frequency measures. Measures of frequency and duration of spells may be used independently of the latent variable measuring food insecurity.
Survey Vehicles to Measure Food Insecurity and Hunger
Recommendation 6-1: USDA should continue to collaborate with the National Center for Health Statistics to use the National Health and Nutrition Examination Survey to conduct research on methods of measuring household food insecurity and individual hunger and the consequences for nutritional intake and other relevant health measures.
Recommendation 6-2: USDA should carefully review the strengths and weakness of the National Health Interview Survey in relation to the Current Population Survey in order to determine the best possible survey vehicle for the Food Security Supplement at a future date. In the meantime, the Food Security Supplement should continue to be conducted in the Current Population Survey.
Recommendation 6-3 :USDA should explore the feasibility of funding a one-time panel study, preferably using the Survey of Income and Program Participation, to establish the relationship between household food insecurity and individual hunger and how they co-evolve with income and health.
Download the full report from the National Academies' website.
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