The impact of the Oakland sugar-sweetened beverage tax on bottled soda and fountain drink prices in fast-food restaurants

Impact of soda tax on beverage price, sale, purchase, and consumption in the US: a systematic review and meta-analysis of natural experiments

Background

As a primary source of added sugars in the US diet, sugar-sweetened beverage (SSB) consumption is presumed to contribute to obesity prevalence and poor oral health. We systematically synthesized and quantified evidence from US-based natural experiments concerning the impact of SSB taxes on beverage prices, sales, purchases, and consumption.

Methods

A keyword and reference search was performed in PubMed, Web of Science, Cochrane Library, Scopus, and EconLit from the inception of an electronic bibliographic database to Oct 31, 2022. Meta-analysis was conducted to estimate the pooled effect of soda taxes on SSB consumption, prices, passthrough rate, and purchases.

Results

Twenty-six natural experiments, all adopting a difference-in-differences approach, were included. Studies assessed soda taxes in Berkeley, Oakland, and San Francisco in California, Philadelphia in Pennsylvania, Boulder in Colorado, Seattle in Washington, and Cook County in Illinois. Tax rates ranged from 1 to 2 ¢/oz. The imposition of the soda tax was associated with a 1.06 ¢/oz. (95% confidence interval [CI] = 0.90, 1.22) increase in SSB prices and a 27.3% (95% CI = 19.3, 35.4%) decrease in SSB purchases. The soda tax passthrough rate was 79.7% (95% CI = 65.8, 93.6%). A 1 ¢/oz. increase in soda tax rate was associated with increased prices of SSBs by 0.84 ¢/oz (95% CI = 0.33, 1.35).

Conclusion

Soda taxes could be effective policy leverage to nudge people toward purchasing and consuming fewer SSBs. Future research should examine evidence-based classifications of SSBs, targeted use of revenues generated by taxes to reduce health and income disparities, and the feasibility of redesigning the soda tax to improve efficiency.

Outcomes Following Taxation of Sugar-Sweetened Beverages: A Systematic Review and Meta-analysis

Importance

More than 45 countries and several local jurisdictions have implemented sugar-sweetened beverage (SSB) taxes to improve nutrition and population health, and evidence on their outcomes to date is essential to inform policy discussions. Responding to this need, the World Health Organization commissioned a systematic literature review on the outcomes of fiscal policies, including SSB taxes.

Objective

To assess the associations of implemented SSB taxes with prices, sales, consumption, diet, body weight, product changes, unintended consequences, health, and pregnancy outcomes.

Data Sources

Searches of 8 bibliographic databases (Business Source Complete, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, CINAHL, EconLit, PsycINFO, PubMed, and Scopus) were performed from database inception through June 1, 2020, with no language or setting restrictions. Grey literature was assessed using 14 sources and government websites.

Study Selection

The review included primary studies of implemented SSB taxes.

Data Extraction and Synthesis

The review followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. For prices, sales and consumption, results were meta-analyzed using a 3-level random-effects model. Study quality was assessed at the outcome level.

Main Outcomes and Measures

Tax pass-through rate for prices, percentage reduction in SSB demand, and price elasticity of demand for sales and consumption. Heterogeneity was assessed using τ2 and the I2 statistic.

Results

A total of 86 articles were eligible, with 62 studies contributing to the meta-analysis. The overall tax pass-through rate was 82% (95% CI, 66% to 98%; P < .001, I2 = 99%), suggesting tax undershifting. The demand for SSBs was highly sensitive to tax-induced price increases, with the price elasticity of demand of -1.59 (95% CI, -2.11 to -1.08; P < .001; I2 = 100%) and a mean reduction in SSB sales of 15% (95% CI, -20% to -9%; P < .001; I2 = 100%). There was no evidence of substitution to untaxed beverages, and changes in SSB consumption were not significant. The narrative synthesis found reformulation and reduced sugar content of taxed beverages for tiered taxes, cross-border shopping in most studies of local-level taxes, and no negative changes in employment. Data on the heterogeneity of SSB tax outcomes across subpopulations were limited.

Conclusions and Relevance

In this systematic review and meta-analysis of implemented SSB taxes worldwide, SSB taxes were associated with higher prices and lower sales of taxed beverages.

Sugar-Sweetened Beverages and Depressive and Social Anxiety Symptoms Among Children and Adolescents Aged 7–17 Years, Stratified by Body Composition

Background

Rare studies investigated the associations between sugar-sweetened beverage (SSB) consumption with depressive and social anxiety symptoms among children and adolescents, particularly in different stratification of body composition, which was our purpose.

Methods

A cross-sectional survey of children and adolescents aged 7–17 years was conducted in Beijing, China, in 2020, with an average age of 12.07 (SD: 3.09) years. Children's Depression Inventory (CDI) questionnaires and social anxiety scale for children (SASC) were completed in the baseline questionnaires. SSB consumption and body composition were assessed using child-reported questionnaires and a GE Healthcare Lunar iDXA dual-energy X-ray bone densitometer. Multivariate logistic regression was used to assess the associations between SSB consumption with depressive and social anxiety symptoms. Confounders were evaluated by child-reported and parental questionnaires, including age, sex, parental educational attainment, maternal smoking status, single-child status, BMI, incomes, fruit consumption, physical activity, screen time, and the frequency of fried food consumption. Stratified analyses were performed to explore whether the associations were influenced by body composition.

Results

A total of 1,311 children and adolescents, including 658 boys and 653 girls, were included in the final analysis. There were 13.96 and 29.75% of the study population with depressive and social anxiety symptoms, respectively. Overall, about 63.77% of the children and adolescents consumed SSB, and the average SSB intake was 0.35 servings per day. In the fully adjusted model, compared to participants who did not consume SSB each day, SSB consumption of ≥1 servings/day was positively associated with depressive symptoms [odds ratio (OR) = 2.28, 95% CI = 1.30–4.01] and social anxiety (OR = 1.10, 95% CI = 0.69–1.77), though the latter did not reach statistical significance. When individuals had higher body fat or lower fat-free mass (FFM) or muscle, the ORs of depressive symptoms were more evident among children and adolescents who drank SSB for ≥1 servings/day (P < 0.05).

Conclusion

Higher consumption of SSB could be associated with increased OR of depressive symptoms in children and adolescents. The association remained robust, especially in groups with higher body fat or lower fat-free mass or muscle.

Purchases of Nontaxed Foods, Beverages, and Alcohol in a Longitudinal Cohort After Implementation of the Philadelphia Beverage Tax

BACKGROUND

Evidence suggests that sweetened beverage taxes reduce taxed beverage purchases, but few studies have used individual-level data to assess whether these taxes affect purchases of nontaxed foods, beverages, and alcohol. Additionally, research has not examined whether sweetened beverage taxes influence restaurant purchases.

OBJECTIVES

We assessed changes in individuals' purchases of taxed beverage types; low-calorie/low-added-sugar nontaxed beverages; high-calorie/high-added-sugar nontaxed beverages, foods, and alcohol; and beverages from restaurants following implementation of the 1.5 cent-per-ounce Philadelphia sweetened beverage tax.

METHODS

A longitudinal cohort of adult sugar-sweetened beverage consumers in Philadelphia (n = 306; 67% female; mean age: 43.9 years) and Baltimore (n = 297; comparison city without a beverage tax; 58% female; mean age: 41.7 years) submitted all food and beverage receipts during 2-week periods at baseline and at 3, 6, and 12 months posttax. Difference-in-differences analyses compared changes in purchases from pre- to posttax in Philadelphia to changes in Baltimore.

RESULTS

Purchases of taxed juice drinks [ratio of incidence rate ratios (RIRR) = 0.62; 95% CI, 0.42-0.91], but not other taxed beverage types, decreased in Philadelphia compared to Baltimore following the tax. Analyses did not find changes in purchases of low-calorie/low-added-sugar nontaxed beverages, such as water or milk. Additionally, analyses did not find increases in purchases of most high-calorie/high-added-sugar nontaxed products, including alcohol, juice, candy, sweet snacks, salty snacks, and desserts. Purchases of beverage concentrates increased in Philadelphia (RIRR = 2.22; 95% CI, 1.39-3.54).

CONCLUSIONS

In this difference-in-differences analysis, the Philadelphia beverage tax was associated with reduced purchases of taxed juice drinks. Purchases of beverage concentrates increased after the tax, but no increases were observed for other high-calorie/high-added-sugar nontaxed foods, beverages, or alcohol.

Sugar-Sweetened Beverage Reduction Policies: Progress and Promise

Evidence showing the effectiveness of policies to reduce the consumption of sugar-sweetened beverages (SSBs) is growing. SSBs are one of the largest sources of added sugar in the diet and are linked to multiple adverse health conditions. This review presents a framework illustrating the various types of policies that have been used to reduce SSB exposure and consumption; policies are organized into four categories (financial, information, defaults, and availability) and take into consideration crosscutting policy considerations (feasibility, impact, and equity). Next, for each category, we describe a specific example and provide evidence of impact. Finally, we discuss crosscutting policy considerations, the challenge of choosing among the various policy options, and important areas for future research. Notably, no single policy will reduce SSB consumption to healthy levels, so an integrated policy approach that adapts to changing market and consumption trends; evolving social, political, and public health needs; and emerging science is critical.

Longer-term impacts of the Oakland, California, sugar-sweetened beverage tax on prices and volume sold at two-years post-tax

Sugar-sweetened beverage (SSB) consumption is associated with obesity and independently associated with type 2 diabetes and cardiovascular disease. Not only is obesity a growing public health problem, but it is also most recently associated with increased risk of severe illness from COVID-19. Taxes on SSBs are a policy tool used to help curb SSB consumption and are currently implemented in 7 U.S. cities and more than 40 countries. On July 1, 2017, Oakland, California, implemented a 1-cent/ounce tax on SSBs with ≥25 kilocalories/12 ounces. This study estimated the impact of the Oakland tax on prices, volume sold, and cross-border shopping two-years post-tax relative to one-year pre-tax. Universal product code-level Nielsen retail scanner data on non-alcoholic beverage sales were analyzed using a difference-in-differences design with Sacramento, California, as the comparison site. Taxed beverage prices increased by 0.67 cents/ounce, on average, in Oakland relative to Sacramento, corresponding to 67% pass-through. Taxed beverage volume sold decreased by 18% in Oakland relative to Sacramento, with a larger decrease for family-size beverages (23%) relative to individual-size beverages (8%). There was a 9% increase in volume sold of taxed beverages in the two-mile border area surrounding Oakland relative to the Sacramento border area, driven by a 12% increase for family-size taxed beverages. After accounting for this cross-border shopping, there was a net decrease of 6% in taxed beverage volume sold in Oakland. There was no significant change in untaxed beverage volume sold in either Oakland or its border area relative to their respective comparison sites, suggesting there was no substitution to untaxed beverages and cross-border shopping may have been limited to taxed beverages. This two-year post-tax study of the Oakland SSB tax adds to the limited number of longer-term evaluations of local U.S. SSB taxes.

Association of a Sweetened Beverage Tax With Purchases of Beverages and High-Sugar Foods at Independent Stores in Philadelphia

Importance

The relationship between a sweetened beverage tax and changes in the prices and purchases of beverages and high-sugar food is understudied in the long term and in small independent food retail stores where sugar-sweetened beverages are among the most commonly purchased items.

Objective

To examine whether a 1.5 cent-per-fluid-ounce excise tax on sugar- and artificially sweetened beverages Philadelphia, Pennsylvania, was associated with sustained changes in beverage prices and purchases, as well as calories purchased from beverages and high-sugar foods, over 2 years at small independent stores.

Design, Setting, and Participants

This cross-sectional study used a difference-in-differences approach to compare changes in beverage prices and purchases of beverages and high-sugar foods (candy, sweet snacks) at independent stores in Philadelphia and Baltimore, Maryland (a nontaxed control) before and 2 years after tax implementation, which occurred on January 1, 2017. Price comparisons were also made to independent stores in Philadelphia's neighboring counties.

Main Outcomes and Measures

Changes in mean price (measured in cents per fluid ounce) of taxed and nontaxed beverages, mean fluid ounces purchased of taxed and nontaxed beverages, and mean total calories purchased from beverages and high-sugar foods.

Results

Compared with Baltimore independent stores, taxed beverage prices in Philadelphia increased 2.06 cents per fluid ounce (95% CI, 1.75 to 2.38 cents per fluid ounce; P < .001), with 137% of the tax passed through to prices 2 years after tax implementation, while nontaxed beverage prices had no statistically significant change. A total of 116 independent stores and 4738 customer purchases (1950 [41.2%] women; 4351 [91.8%] age 18 years or older; 1006 [21.2%] White customers, 3185 [67.2%] Black customers) at independent stores were assessed for price and purchase comparisons. Purchases of taxed beverages declined by 6.1 fl oz (95% CI, -9.9 to -2.4 fl oz; P < .001), corresponding to a 42% decline in Philadelphia compared with Baltimore; there were no significant changes in purchases of nontaxed beverages. Although there was no significant moderation by neighborhood income or customer education level, exploratory stratified analyses revealed that declines in taxed beverage purchases were larger among customers shopping in low-income neighborhoods (-7.1 fl oz; 95% CI, -13.0 to -1.1 fl oz; P = .001) and individuals with lower education levels (-6.9 fl oz; 95% CI, -12.5 to -1.3 fl oz; P = .001).

Conclusions and Relevance

This cross-sectional study found that a tax on sweetened beverages was associated with increases in price and decreases in purchasing. Beverage excise taxes may be an effective policy to sustainably decrease purchases of sweetened drinks and calories from sugar in independent stores, with large reductions in lower-income areas and among customers with lower levels of education.

Longer-term impacts of sugar-sweetened beverage taxes on fast-food beverage prices: evidence from Oakland, California, 2-year post-tax

OBJECTIVE

To evaluate the effect of a sugar-sweetened beverage (SSB) tax implemented in Oakland, California, in July 2017, on prices of beverages sold in fast-food restaurants 2-year post-tax.

DESIGN

Using a difference-in-differences (DID) approach, we analysed beverage price data collected from fast-food restaurants 1-month pre-tax and 2-year post-tax in Oakland (intervention site) and Sacramento, California (comparison site). Separate linear regression models were used to estimate the impact of the tax on prices of bottled regular soda, bottled diet soda, bottled unsweetened beverages and fountain drinks.

SETTING

Oakland and Sacramento, California, USA.

PARTICIPANTS

Chain and non-chain fast-food restaurants (n 85).

RESULTS

DID estimates indicate that in fast-food restaurants, on average, the price of bottled regular soda increased by 1·44 cents/oz (95 % CI 0·50, 2·73) (tax pass-through rate of 144 %) and the price of bottled diet soda increased by 1·17 cents/oz (95 % CI 0·07, 2·13). No statistically significant differences were found between bottled regular and diet soda price increases. Price effects for unsweetened beverages and fountain drinks were not statistically significant. Further, the estimated price change for fountain drinks was nearly zero.

CONCLUSIONS

Findings suggest that the effectiveness of SSB taxes in discouraging SSB consumption may be limited in fast-food restaurants in Oakland, California, because there were similar price increases in taxed and untaxed bottled soda and no changes in fountain drink prices.