1 / 14

Suladda Pongutta HPPU Journal Club

Suladda Pongutta HPPU Journal Club. Implications of sugar-sweetened beverages (SSB) tax when substitutions to non-beverage items are considered. Introduction. Proposed soda tax - another 1 cent/ounce 8-10% reduction in SSB consumption

moral
Télécharger la présentation

Suladda Pongutta HPPU Journal Club

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Suladda Pongutta HPPU Journal Club Implications of sugar-sweetened beverages (SSB) tax when substitutions to non-beverage items are considered

  2. Introduction Proposed soda tax - another 1 cent/ounce 8-10% reduction in SSB consumption - increase SSB tax by 18% prevent 145,000 adult-obesity cases Argument - If this can prevent sweet-addicted people from searching for substitutes Fail to raise SSB tax

  3. Introduction GAPS of knowledge • Prior studies did not control for potential price endogeneity. • Prior studies did not take other possible substitutions into account. (apart from beverage family) • If the switches increase consumption of sodium and fat?

  4. Objectives • To predict the effects of the proposed rate of SSB tax, when considering other possible substitutions, on - energy consumption and body weight - fat & sodium consumption

  5. Data management Purchase record; payment + units + socio-demographic (Nielsen Homescan panel) Nutrition info. (Glandson 2009 & USDA) SSB; soda, fruit drinks, sport energy Other bevs; ; fruit juices, milk, diet soda food; candies, cookies, salty snacks, ice cream, yogurt, ready-to-eat cereal, french fries, pizza, frozen dinners, caned fruits & vegetables & soups. data in 2006 Q1 Q2 Q3 Q4 28,584 households 114,336 individuals (> 6 yrs old.)

  6. Data analysis Each food item 1 Disaggregate regression Instrumental variable model, IV Exogenous model 2 If 20% price increase has any effects on…… • Fat intake • Sodium intake • Energy intake • Body weight • Fat intake • Sodium intake • Energy intake • Body weight 3

  7. Exogenous models • Two part models of GLM family were used to deal with the skew of purchasing data • Aggregate regression was run to check the robustness of the total change of nutrient purchased

  8. Instrumental variable models • Variables - x; log of price index of SSBs (created by instrumental variable model) - y; fat & sodium & energy intake - control; log of price index of other food items, household per capita income, proportion of adults, ID of 52 Nielsen markets, socio-demographic characteristics. Control biases when creating instrument (price index) - weighted price index by using inverse of Euclidian distances between neighbors - excluded prices of HH living in the same tract to avoid common tract-specific demand shock

  9. Instrumental variable models • Models to estimate the effect - two-stage residual inclusion instrumental variable approach - estimate the effect of 20% price increase by using the incremental variations of nutrients purchased derived from the model mentioned earlier - convert the estimated reductions in calories into weight loss (alternative method, up to age, gender, fat & lean composition) • Quantile regression to assess the effect of tax on 25th , 50th , 75th percentiles of purchase (created instrument using the same model)

  10. Results Overall • SSBs taxes reduced daily store-bought energy by 21.2 (exogenous) and 13.2 kcal (IV) • slightly decreased fat intake (-21 & -26 cg/day; respectively) • Decrease sodium intake 10 (exogenous) & 6.8 mg/day (IV) but the effect was vague when running IV Disaggregated effects (IV) • Lower energy was mostly from lower consumption of soda (-5.5 kcal/day) and fruit drinks (-7.0) • The major substitute was fruit juices (+2.5 kcal/day) • Only food substitute was canned soups

  11. Results Disaggregated effects (IV) • Energy intake from salty snacks and ice cream decreased with lower energy from SSBs (-6.3 & - 4.8 kcal, respectively) and were the major contributors driving fat intake down • The major contributors of downward trend of sodium intake were soda (-1.6 mg/day), fruit drinks (-3.9 ), candy (-1.9) and ice cream (-1.6) while increasing consumption of canned soup increased sodium intake by 14.7 mg/day

  12. Results Arc-elasticity From energy to body weight • 24.3 kcal/day = 1.6 pounds in the 1st year or 2.9 pounds in the 10th year Big fans of SSBs and higher-energy consumers had lower price- elasticity but incremental change was high enough to cut their weights off -1.40 - 4.47 Q1 Q4

  13. Discussion • Data from purchasing survey were self-reported • The energy got from the 19 food categories accounted for only 518 kcal/day • Disadvantage; did not account for the income effect but the effect seemed to be limited • Advantages; • Nutrient purchased at the product level • Prevent endogeneity and measurement error

  14. Conclusion • Tax SSBs decrease energy and fat intake • No substitutions except for fruit juices and canned soups • Tax SSBs for 20% price increase may decrease unhealthy diet consumption and BW • SSBs tax proposed by this study seemed to be regressive but the effect can be reduced by performing sale tax • To tax SSBs, potential cost must be weighted against benefits • The taxes should be used in health promotion to gain more effect

More Related