Using economics to inform nutrition interventions: Evidence from developing countries

1. Using economics to inform nutrition interventions:Evidence from developing countries Will Masters Friedman School of Nutrition Science & Policy and Department of Economics, Tufts University http://nutrition.tufts.edu/profile/william-masters

2. Who We Are About T-GOC Tufts Global Obesity Collaborative (T-GOC) is an initiative to foster collaborations on topics relating to obesity across Tufts University, with a focus on both domestic and global obesity. Funding for this initiative is provided by the Office for the Vice Provost for Research, as part of the university’s Strategic Plan for Research. Diversity and Inclusion T-GOC places utmost importance on diversity and inclusion. T-GOC promotes avoidance of weight bias and stigmatization, including through use of appropriate, sensitive, and respectful language and images.

3. Using economics to inform nutrition interventions randomized incentives | market prices | obesity gradients “Economics is the study of people in the ordinary business of life” • Economists draw on structural models of behavior and interactions to study: • individual behavior (e.g. food choice) • societal outcomes (e.g. food prices) • impacts of intervention (programs and policies) • Three examples for obesity research: • Randomized incentives to elicit & measure impact of behavior change • Indexes of market prices to measure affordability of healthier diets • Distinguishing household wealth from national income to see change in obesity-wealth gradient within and between countries -- Alfred Marshall, Principles of Economics (1890)

4. Using economics to inform nutrition interventions randomized incentives | market prices | obesity gradients Our three examples are: a) Randomized trials of bonuses for childcare workers to reduce malnutrition in India b) Price indexes to measure the Changing Affordability of Nutritious Diets in Africa & S. Asia (CANDASA) c) New project: Data visualization of national vs. household income to reveal change in the SES-obesity gradient across countries

5. Using economics to inform nutrition interventions randomized incentives | market prices | obesity gradients Randomized incentives can reveal what works • Aim of randomized trial was to help Indian ICDS childcare centers reduce underweight • We used contests among caregivers in Chandigarh, offering small cash incentives for improved outcomes to reveal what actions led to observed improvements • Trial #1: pay-for-performance vs fixed bonus • Control group (fixed salary only) • Pay-for-performance (200 Rs/child improved) • Fixed bonus (600 Rs to all workers) • Trial #2: winner-take-all vs shared rewards • Traditional contest (one winner) • Proportional prizes (share of children improved)

6. Using economics to inform nutrition interventions randomized incentives | market prices | obesity gradients Incentives focus workers’ attention Abstract This paper tests the effectiveness of performance pay and bonuses among government child-care workers in India. In a controlled study of 160 ICDS centers serving over 4000 children, we randomly assign workers to either fixed bonuses or payments based on the nutritional status of children in their care, and also collect data from a control group receiving only standard salaries. In all three study arms mothers receive nutrition information. We find that performance pay reduces underweight prevalence by about 5 percentage points over 3 months, and height improves by about one centimeter. Impacts on weight continue when incentives are renewed and return to parallel trends thereafter. Fixed bonuses are less expensive but lead to smaller and less precisely estimated effects than performance pay, especially for children near malnutrition thresholds. Both treatments improve worker effort and communication with mothers, who in turn feed a more calorific diet to children at home.

7. Using economics to inform nutrition interventions randomized incentives | market prices | obesity gradients The best incentives help everyone do better Abstract We conduct a randomized trial to compare incentives for improved child outcomes among salaried caregivers in Chandigarh, India. A contest whose prize is divided among workers in proportion to measured gains yielded more improvement than a winner-take-all program. In our population of about 2000 children served by 85 workers, using proportional rewards led to weight-for-age malnutrition rates that were 4.3 percentage points lower at 3 months (when rewards were paid) and 5.9 points lower at 6 months (after the contest had ended), with mean weight-for-age z scores that were 0.071 higher at 3 months, and 0.095 higher at 6 months. Proportional bonuses led to larger and more sustained gains because of better performance by lower-ranked workers, whose efforts were not rewarded by a winner-take-all prize. Results are consistent with previous laboratory trials and athletic events, demonstrating the value of proportional rewards to improve development outcomes.

8. Using economics to inform nutrition interventions randomized incentives | market prices | obesity gradients New price indexes can track the cost of healthier foods

9. Using economics to inform nutrition interventions randomized incentives | market prices | obesity gradients New price indexes can track the cost of healthier foods Abstract Policies and programs often aim to improve the affordability of nutritious diets, but existing food price indexes are based on observed quantities that may not meet nutritional goals. To measure changes in the cost of reaching international standards of diet quality, we introduce a new cost of diet diversity index based on the lowest-cost way to include at least five different food groups as defined by the widely used minimum dietary diversity for women (MDD-W) indicator and compare that to a Cost of Nutrient Adequacy indicator for the lowest-cost way to meet estimated average requirements of essential nutrients and dietary energy. We demonstrate application of both indexes using national average monthly prices from two very different sources: an agricultural market information system in Ghana (2009–14) and the data used for national consumer price indexes in Tanzania (2011–15). We find that the cost of diet diversity index for Ghana fluctuated seasonally and since mid-2010 rose about 10% per year faster than national inflation, due to rising relative prices for fruit, which also drove up the cost of nutrient adequacy. In Tanzania there were much smaller changes in total daily costs, but more adjustment in the mix of food groups used for the least-cost diet. These methods can show where and when nutritious diets are increasingly (un)affordable, and which nutritional criteria account for the change. These results are based on monthly national average prices, but the method is generalizable to other contexts for monitoring, evaluation, and assessment of changing food environments.

10. Using economics to inform nutrition interventions randomized incentives | market prices | obesity gradients New price indexes can track the cost of healthier foods Next Wednesday, online at www.ifpri.org/events

11. Using economics to inform nutrition interventions randomized incentives | market prices | obesity gradients Global anthropometry can track emergence of obesity • New project with PhD student Bianca Braga • Use maternal anthropometry collected for DHS surveys in low- and middle-income countries • Nationally representative of total population • Respondents have at least one child under 5 • Anthropometry matched to household assets, education etc. • Initial results from ~1.4 million nonpregnant women in 26 countries • Key finding is emergence of SES gradient above $3,000/yr in purchasing power parity terms Prevalence of overweight (BMI=25-30) Prevalence of obesity (BMI>30) Richest 20% Richest 20% Poorest 20% Poorest 20% National income, in USD/person: 4,000 4,000 8,000 8,000 2,000 2,000 Guatemala Rwanda Bangladesh Example countries:

12. Using economics to inform nutrition interventions randomized incentives | market prices | obesity gradients There are many opportunities to use economics in obesity research Three examples here: • Randomizing incentives, as in our India trial, to elicit effort and measure behavior change and its impact on outcomes • Measuring the food environment, as in our CANDASA price indexes to measure affordability of healthier diets • Distinguishing household from environment factors, as in new work on the rise of obesity in low-income countries …but also choice experiments, estimation of price and income demand elasticities, impact assessment and measurement of cost-effectiveness and other useful tools!