The WIC Program

• ERS Reports
• Contractor and Cooperator Reports
• Amber Waves
• RIDGE (formerly Small Grants) WIC Projects
• Journal Articles

ERS Reports

WIC Participation Patterns: An Investigation of Delayed Entry & Early Exit--Despite the health benefits of WIC participation, many eligible women do not participate during pregnancy, and many households exit WIC when a participating child turns 1 year old. Using the first two waves of the Early Childhood Longitudinal Study-Birth Cohort (ECLS-B), this study shows that households that are more economically advantaged are more likely to delay entry into the program or exit after a child turns 1 year old. (December 2010)

Rising Infant Formula Costs to the WIC Program: Recent Trends in Rebates and Wholesale Prices--This study estimated that 57 to 68 percent of all infant formula sold in the United States was purchased through WIC, based on 2004-06 data, and that formula costs to the WIC program have increased. Typically, WIC State agencies receive substantial rebates from manufacturers for each can of formula provided through the program. After adjusting for inflation, net wholesale prices increased by an average 73 percent for 26 fluid ounces of reconstituted formula between States' contracts in effect in December 2008 and the States' previous contracts. As a result of the increase in real net wholesale prices, WIC paid about $127 million more for infant formula over the course of a year. (February 2010)

The WIC Program: Background, Trends, and Economic Issues--This report presents comprehensive background information on the WIC program-how the program works, its history, trends, and the characteristics of the population served. Also examined are current issues facing WIC, focusing mainly on those with important economic implications. (April 2009)

WIC and the Battle Against Childhood Overweight--The number of children at risk of being overweight has grown in the past two decades, as has the number of young children whose families participate in the WIC Program. Are these increases connected? The answer appears to be "no." However, children in low-income families, especially low-income, Mexican-American families, are more likely to be overweight. (April 2009)

Economic Linkages Between the WIC Program and the Farm Sector--In fiscal 2008, the $4.6 billion of food purchased with vouchers from WIC generated $1.3 billion in farm revenue. Because WIC participants would have purchased some of these foods with their own money in the absence of the program, the net addition to farm revenue from WIC is estimated at $331 million and the net increase in full-time-equivalent farm jobs at 2,640. The study uses an Input-Output Multiplier Model to derive these estimates and assumes that recent revisions in the WIC food packages were implemented in all States. (March 2009)

Informing Food and Nutrition Assistance Policy: 10 Years of Research at ERS--Since 1998, Congress has provided funds to ERS to study and evaluate the Nation's domestic food and nutrition assistance programs. ERS has become the premier source of food and nutrition assistance research in the United States, sponsoring over 600 publications on a wide range of topics related to food and nutrition assistance. This report highlights some of the key research conducted during the FANRP program's first decade. (December 2007)

Recent Trends and Economic Issues in the WIC Infant Formula Rebate Program--Over half of all infant formula sold in the United States is purchased through the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC). Typically, WIC State agencies obtain substantial discounts in the form of rebates from infant formula manufacturers for each can of formula purchased through the program. This analysis suggests that retail markup accounts for most of the cost to WIC of infant formula in most States. Both retail markup and net wholesale price, however, have increased over time, with the recent increase coinciding with the introduction of higher priced supplemented infant formulas. (August 2006)

WIC and the Retail Price of Infant Formula--Rebates from infant formula manufacturers to State WIC agencies support over one-quarter of all WIC participants. However, WIC and its infant formula rebate program may significantly affect the infant formula prices faced by non-WIC consumers. This report presents findings from the most comprehensive national study of infant formula prices at the retail level. For a given set of wholesale prices, WIC and its infant formula rebate program resulted in modest increases in the supermarket price of infant formula, especially in States with a high percentage of WIC formula-fed infants. However, lower priced infant formulas are available to non-WIC consumers in most areas of the country, and the number of lower priced alternatives has increased. (January 2005)

Interstate Variation in WIC Food Package Costs: The Role of Food Prices, Caseload Composition, and Cost-Containment Practices--Food prices within States affect average monthly costs of State food benefits packages provided by the WIC program more than variations in WIC caseload composition do. In addition, cost-containment practices by State WIC agencies provide different levels of cost savings in different areas, contributing to interstate variation in benefits package costs. This study is one of the few to examine the degree to which food prices, caseloads, and cost-containment practices influence costs of State WIC food benefits packages. Because limited data exist on the actual food items that WIC participants purchase, the study used a scanner dataset of supermarket transactions and other sources to estimate the average monthly cost of WIC food benefits in several areas. (January 2005)

Contractor and Cooperator Reports

The Effects of Changes in WIC Food Packages on Redemptions--This study of Wisconsin participants in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) found that the vast majority of WIC participants used some or all of their food instruments 18 months after WIC food package changes were implemented. Most participants purchased all of the prescribed foods, and more than three-quarters of WIC participants used their cash value vouchers (CVVs) for fruits and vegetables. However, the percentage of WIC participants making full purchases with their traditional food instruments decreased compared to the baseline. The change in the proportion of participants who did not use any food instruments was found across all participant categories and racial/ethnic groups, but appears to have affected non-Hispanic Black and non-Hispanic American Indian/Alaska Native participants the most (December 2011). 

Impact of the WIC Program on the Infant Formula Market--This research examines the impact of providing infant formula through the WIC program on the wholesale price of infant formula. The findings show that providing free formula to low-income families is the primary factor in the growth in real wholesale prices of formula but that sole-source contracts not only have reduced the cost of formula to the Government but also have mediated wholesale price growth. (January 2009)

Factors Associated with Iron Status Among WIC Infants and Toddlers in Rural West Virginia--Iron deficiency severe enough to cause anemia may affect children's ability to grow and learn and, consequently, their lifelong productivity and earnings. This study conducted blood screenings of infants and toddlers ages 6-24 months participating in The Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) in West Virginia. Results show that 12 of the 57 infants and toddlers (21 percent) were iron deficient, considerably more than the 4 of 49 (8 percent) with anemia. Because routine screenings are unable to detect iron deficiency before it progresses to anemia, primary prevention of iron deficiency is the only option that may be universally applied. Expert feeding recommendations-such as introducing iron-rich complementary foods after 6 months of age and limiting consumption of milk among children ages 12-24 months to no more than 24 ounces-are useful for promoting adequate intake of readily-available iron and may help prevent iron deficiency. (December 2007)

An Assessment of the Impact of Medicaid Managed Care on WIC Program Coordination With Primary Care Services--Coordination between the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) and Medicaid has been an important component to ensuring access to primary care services for WIC clients. This study examines how increased use of managed care in the Medicaid program has affected WIC program coordination efforts. According to the study sample, 72 percent of State Medicaid agencies report that Managed Care Organizations (MCOs) are required to inform their members about WIC. About 43 percent of State WIC agencies sampled in the study have a formal agreement with a State Medicaid agency, generally revolving around data sharing, referrals, and provision of special metabolic infant formulas. The agreements, however, often lack specific details on how services should be coordinated. Some local WIC agencies and MCOs have implemented innovative approaches to coordination such as including Medicaid staff at WIC clinics to help clients with enrollment, information sharing to promote targeted outreach efforts, helping clients identify providers and resources, and transportation costs paid by MCOs for WIC clients to attend WIC appointments. (September 2007)

Using Point-of-Purchase Data To Evaluate Local WIC Nutrition Education Interventions: Feasibility Study--The effect of nutrition education-an important component of many Federal food assistance programs-on participants' food consumption behavior is difficult to ascertain. This study finds that combining point-of-purchase data with State data on the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) is a feasible method to assess behavioral changes in WIC participants. The major obstacle to using these data to evaluate WIC participant food-purchasing behaviors is the recruitment of a large enough sample of stores for a representative sample of WIC participants. (January 2007)

Effects of Food Assistance and Nutrition Programs on Nutrition and Health: Volume 3, Literature Review--This report provides a comprehensive review and synthesis of published research on the impact of USDA's food and nutrition assistance programs, including WIC, on participants' diet and health outcomes. The report is one of four volumes produced by a larger study, including Volume 1, Research Design; Volume 2, Data Sources; and Volume 4, Executive Summary of the Literature Review. (December 2004)

Amber Waves

Amber Waves, ERS's magazine, is a window into the agency's broad research program, covering production agriculture, food safety and nutrition, the food industry, rural economies, agricultural trade, and farm-related environmental issues. Published four times a year in web and print editions, Amber Waves contains in-depth feature articles, research findings, previews of research in the works, and statistics, including a variety of articles related to WIC and other food and nutrition assistance programs. The following articles are particularly relevant to WIC:

• WIC Infants Less Likely To Be Exclusively Breastfed, December 2010
• Most Infant Formula Purchased Through WIC, March 2010
• WIC Not Linked to Overweight in Children, December 2009
• Can Low-Income Americans Afford a Healthy Diet?, November 2008
• Despite Higher Food Prices, Percent of U.S. Income Spent on Food Remains Constant, September 2008
• How Much Time Do Americans Spend Eating? September 2008

• Cost of Infant Formula for the WIC Program Rising, November 2006
• Adjusting for Living Costs Can Change Who Is Considered Poor, November 2006
• Food Assistance: How Strong Is the Safety Net?, September 2006
• Children's Diets and WIC, June 2006
• Prices Dominate Interstate Variations in WIC Food Costs, February 2005
• Sharing the Economic Burden: Who Pays for WIC's Infant Formula?, September 2004

RIDGE (formerly Small Grants) WIC Projects

FANRP's RIDGE Program has funded several research projects of relevance to WIC, including those listed below:

Kavanagh, K., and C. Springer. Attitudes or Income? What Determines Whether Mothers in the WIC Program Dilute or Concentrate Baby Formula .

Kavanagh, K. Prevalence of Accurately Reconstituted Infant Formula in the WIC Population and in the Non-WIC-Eligible Population: Exploring Maternal Knowledge, Attitudes, and Practices of Infant Formula Preparation.

Brown, B., and T. Burns. Implementing Strategies That Increase Healthy Food Consumption in Local Grocery Stores on a Northern Plains Indian Reservation.

Gittelsohn, J., and M. Qi. Understanding the Impact of Food Assistance Program Usage on Diet Among American Indians.

Maalouf, Z., and K.G. Dewey. The Use of the New World Health Organization Growth Standards To Identify Trends and Determinants of Overweight in WIC Infants and Children.

Odoms-Young, A., S. Zenk, and N. Chavez. WIC Vendor Access and Fruit and Vegetable Availability in Northern Illinois.

Lofton, K., and C. Connell. Examining Relationships Among Obesity, Food Insecurity, Stress, and Emotional Eating in Low-Income Caregivers of Head Start Children.

Laraia, B.A., M. Bentley, and J. Borja. Food Security and Feeding Strategies.

Ziol-Guest, K.M., and D.C. Hernandez. Women, Infants, and Children (WIC): Effect on Infant Feeding Practices and Children's Health and Well-Being.

Metallinos-Katsaras, E., J. Kallio, A. Must, P. Wilde, and K. Gorman. A Longitudinal Study of Food Insecurity on Overweight in Preschool Children.

Bitler, M., and J. Currie. Medicaid at Birth, WIC Take Up, and Children's Outcomes. A Final Report to the IRP/USDA Small Grants Program .

Chatterji, P., K. Bonuck, S. Dhawan, and N. Deb. WIC Participation and the Initiation and Duration of Breastfeeding .

Swann, C. The Dynamics of WIC Prenatal Participation .

Journal Articles

Yunzal-Butler, C., T. Joyce, and A. Racine. "Maternal Smoking and the Timing of WIC Enrollment: A Response to Davis, Lazariu and Sekhobo," Maternal and Child Health Journal 14(3):474-77, May 2010.

Ziol-Guest, K., and D. Hernandez. "First- and Second-Trimester WIC Participation Is Associated with Lower Rates of Breastfeeding and Early Introduction of Cow's Milk during Infancy," Journal of the American Dietetic Association 110(5):702-09, May 2010.

Hoynes, H., M. Page, and A. Stevens. Is a WIC Start a Better Start: Evaluating WIC's Impact on Infant Health Using Program Introduction, National Bureau of Economic Research Working Paper 15589, December 2009.

Jacknowitz, A., and L. Tiehen. "Transitions Into and Out of the WIC Program: A Cause for Concern?" Social Service Review 83(2):151-83, June 2009.

Yunzal-Butler, C., T. Joyce, and A.D. Racine. "Maternal Smoking and the Timing of WIC Enrollment," Maternal and Child Health Journal, epub February 2009.

Tiehen, L., and A. Jacknowitz. "Why Wait? Examining Delayed WIC Participation Among Pregnant Women," Contemporary Economic Policy 26(4):518-38, October 2008.

Kavanagh, K., R. Cohen, M. Heinig, and K. Dewey. "Educational Intervention to Modify Bottle-feeding Behaviors among Formula-feeding Mothers in the WIC Program: Impact on Infant Formula Intake and Weight Gain," Journal of Nutrition Education and Behavior 40(4):244-50, July/August 2008.

Fitch, C.W., M.S. Cannon, G.E. Seidel, D.A. Krummel. "Dietary Factors Affecting Iron Status of Children Residing in Rural West Virginia," West Virginia Medical Journal 104(3):19-22, May-June 2008.

Joyce, T., A. Racine, and C. Yunzal-Butler. "Reassessing the WIC Effect: Evidence from the Pregnancy Nutrition Surveillance System," Journal of Policy Analysis and Management 27(2):277-303, Spring 2008.

Ishdorj, A., H. Jensen, and J. Tobias. "Intra-Household Allocation and Consumption of WIC-Approved Foods: A Bayesian Approach," Advances in Econometrics, Vol. 23: Bayesian Econometric Methods, pp. 157-182, S. Chib, B. Griffiths, G. Koop, and D. Terrell, eds, Emerald Group Publishing Limited, 2008.

Jacknowitz, A., D. Novillo, and L. Tiehen. "Special Supplemental Nutrition Program for Women, Infants, and Children and Infant Feeding Practices," Pediatrics 119(2):281-89, February 2007.

Swann, C. "The Timing of Prenatal WIC Participation," The B.E. Journal of Economic Analysis & Policy 7(1), January 2007.

Whitaker, R., S. Phillips, and S. Orzol.  "Food Insecurity and the Risks of Depression and Anxiety in Mothers and Behavior Problems in Their Preschool-Aged Children," Pediatrics 118(3):e859-68, September 2006.

Whitaker, R., and S. Orzol. "Obesity Among US Urban Preschool Children: Relationships to Race, Ethnicity, and Socioeconomic Status," The Archives of Pediatrics & Adolescent Medicine 160(6):578-84, June 2006.

Herman, D.R., G.G. Harrison, and E. Jenks. "Choices Made by Low-Income Women Provided with an Economic Supplement for Fresh Fruit and Vegetable Purchase,"  Journal of the American Dietetic Association 106(5):740-44, May 2006.

Rose, D., J. Bodor, and M. Chilton. "Has the WIC Incentive to Formula-Feed Led to an Increase in Overweight Children?" Journal of Nutrition 136(4):1086-90, April 2006.

Skalicky, A., A. Meyers, W. Adams, Z. Yang, J. Cook, and D. Frank. "Child Food Insecurity and Iron Deficiency Anemia in Low-Income Infants and Toddlers in the United States," Maternal Child Health Journal 10(2):177-85, March 2006.

Dennison, B., L. Edmunds, H. Stratton, and R. Pruzek. "Rapid Infant Weight Gain Predicts Childhood Overweight," Obesity 14(3):491-99, March 2006.

Murphy, S., J. Foote, L. Wilkens, P. Basiotis, A. Carlson, K. White, and K. Yonemori. "Simple Measures of Dietary Variety Are Associated with Improved Dietary Quality," Journal of the American Dietetic Association 106(3):425-29, March 2006.

Edmunds, L., M. Woelfel, B. Dennison, H. Stratton, R. Pruzek, and R. Abusasha. "Overweight Trends among Children Enrolled in the New York State Special Supplemental Nutrition Program for Women, Infants and Children," Journal of the American Dietetic Association 106(1):113-17, January 2006.

Bonuck, K., M. Trombley, K. Freeman, and D. McKee. "Randomized, Controlled Trial of a Prenatal and Postnatal Lactation Consultant Intervention on Duration and Intensity of Breastfeeding Up to 12 Months," Pediatrics 116(6):1413-26, December 2005.

Schneider, J., M. Fujii, C. Lamp, B. Lonnerdal, K. Dewey, and S. Zidenberg-Cherr. "Anemia, Iron Deficiency and Iron Deficiency Anemia in 12-36-Month Old Children from Low-income Families," American Journal of Clinical Nutrition 82(6):1269-75, December 2005.

Bitler, M.P., and J. Currie. "Does WIC Work? The Effects of WIC on Pregnancy and Birth Outcomes," Journal of Policy Analysis and Management 24(1):73-91, Winter 2005.

Nord, M., and E. Leibtag. "Is the 'Cost of Enough Food' Lower in Rural Areas?" The Review of Regional Studies 35(3):291-310, Winter 2005.

Bitler, M.P., and J. Currie. "The Changing Association Between Prenatal Participation in WIC and Birth Outcomes in New York City: What Does It Mean?" Journal of Policy Analysis and Management 24(4):687-90, Fall 2005.

Joyce, T., D. Gibson, and S. Colman. "The Changing Association Between Prenatal Participation in WIC and Birth Outcomes in New York City," Journal of Policy Analysis and Management 24(4):661-85, Fall 2005.

Bitler, M., and J. Currie. "Medicaid at Birth, WIC Take Up, and Children's Outcomes. A Final Report to the IRP/USDA Small Grants Program," Institute for Research on Poverty, Discussion Paper No. 1246-02, February 2002.

Chatterji, P., K. Bonuck, S. Dhawan, and N. Deb. "WIC Participation and the Initiation and Duration of Breastfeeding," Institute for Research on Poverty, Discussion Paper No. 1246-02, February 2002.

Last updated: Friday, August 03, 2012

For more information contact: Elizabeth Frazao