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Evaluation of School Nutrition Policy. July 25, 2010 Applied and Agricultural Economics Conference Denver, CO Philip Gleason, Ph.D. Mathematica Policy Research. USDA School Meal Programs. National School Lunch Program ( NSLP ) Operates in nearly all public schools
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Evaluation of School Nutrition Policy July 25, 2010 Applied and Agricultural Economics Conference Denver, CO Philip Gleason, Ph.D. Mathematica Policy Research
USDA School Meal Programs • National School Lunch Program (NSLP) • Operates in nearly all public schools • Over 31 million students served each day • FY 2008 budget: $9.3 billion • School Breakfast Program • Operates in 85% of public schools • About 11 million students served each day • FY 2008 budget: $2.4 billion
Program Operations • Participating schools offer meals meeting USDA requirements to all students • Low-income students receive meals free or at reduced-price • Income<130% of poverty Free meals • Income 130-185% of poverty Reduced-price meals • Income>185% of poverty Full-price meals • All meals served are reimbursed by USDA, though at different rates
Key Program Issues • Do meals offered by schools meet dietary standards? • How does program participation affect students? • Impacts on dietary intake • Impacts on BMI / obesity • Are free and reduced-price meals served to eligible students?
Evaluation Strategies • USDA-sponsored national studies • SNDA-I (1991-92): meals offered and dietary intake • SNDA-II (1998-99): meals offered only • SNDA-III (2004-05): meals offered and dietary intake • SNDA-IV (ongoing): meals offered only • Analysis of nationally representative data sets • CSFII (1994-96; 1998) • NHANES (ongoing) • ECLS (ongoing) • Local studies
Characteristics of Schools’ Meals Offered, 2004-05 USDA requirements for most nutrients listed above are based on the 1995 School Meals Initiative for Healthy Children (SMI). Benchmarks for cholesterol, sodium, and fiber based on 2005 Dietary Guidelines for Americans. Source: Crepinsek et al. (2009)
Progress Over Time in Meeting Fat Guideline SMI Target SMI Target Total Fat Saturated Fat *Significantly different from prior time period at the 0.05 level. Source: Gordon et al. (2007); Fox et al. (2001); Burghardt et al. (1993)
Measuring Program Impacts on Children: Challenges • Measuring dietary intake • 24-hour recalls with young children • Reporting error • Estimating usual rather than daily intake • Selection bias • Experimental design usually not feasible • Non-experimental approaches • Control for observables (regression; matching) • Instrumental variables • Fixed effects • Regression discontinuity
Estimated Effects of NSLP on Dietary Intake: Summary • Increased intake of selected vitamins & minerals • Increased food energy intake • No significant association with saturated fat • Increased likelihood of excessive sodium intake (among high school students)
Vitamin and Mineral Intakes, by NSLP Participation * Significantly different from non-participants at the 0.05 level. Mean intakes of calcium and dietary fiber were also significantly higher among participants. Source: Clark and Fox (2009)
Fat, Sodium, and Cholesterol Intakes, by NSLP Participation * Significantly different from non-participants at the 0.05 level. Mean intakes of calcium and dietary fiber were also significantly higher among participants. Source: Clark and Fox (2009)
Food Energy Intake * Significantly different from non-participants at the 0.05 level. Mean intakes of calcium and dietary fiber were also significantly higher among participants. Source: Clark and Fox (2009)
Food Energy Intake: Evidence of Selection Bias? • Estimated impact of NSLP on energy intake at lunch smaller than estimated impact at other meals • Analysis of CSFII data (1994-96) • OLS: Significant impact on lunch intake (30 vs. 26) • Among subsample with intake measured on 1 school day and 1 non-school day • School day: intake higher among participants (29 vs. 26) • Non-school day: intake higher among part. (31 vs. 27) • Fixed Effects: No significant impact
NSLP/SBP Program Integrity • Do ineligible students get free/RP meal benefits? • No income documentation required for applicants • Incentives for overcertification • APEC study (Ponza et al. 2007) • Certification errors for 1 in 5 applicants (most over-certified) • Overpayments represents 7% of total free/RP payments • USDA demonstration of “up-front documentation” didn’t work as intended • No decline in rate on ineligible households getting benefits • Decline in rate of eligible households getting benefits
For more information • SNDA-III study • http://www.mathematica-mpr.com/nutrition/schoolmealsstudy.asp • APEC study • http://www.mathematica-mpr.com/nutrition/apec.asp • Other USDA research on school nutrition policy • http://www.fns.usda.gov/ora/MENU/Published/CNP/cnp.htm