No Evidence of Food or Alcohol Substitution in Response to a Sweetened Beverage Tax

Effectiveness of implemented global dietary interventions: a scoping review of fiscal policies

BACKGROUND

Although the World Health Organisation (WHO) has proposed the use of fiscal policies to mitigate consumption externalities such as overweight and obesity-related diseases, very little is known about the impacts of the different types and framing of national and/or regional fiscal policies that have been implemented over the years. There is the need to provide up-to-date evidence on the impact of fiscal policies that have been enacted and implemented across the globe.

METHODS

We conducted a scoping review of all implemented government fiscal policies in the food and drinks sector to identify the different types of fiscal policies that exist and the scope of their impact on consumers as well as the food environment. Electronic databases such as the Web of Science and Google Scholar were used to search for appropriate literature on the topic. A total of 4,191 articles were retrieved and 127 were synthesized and charted for emerging themes.

RESULTS

The results from this review were synthesized in MS Excel following Arksey & O'Malley (2005). Emerging themes were identified across different countries/settings for synthesis. The results confirms that fiscal policies improve consumers' health; increase the prices of foods that are high in fats, sugar, and salt; increase government revenue; and shift consumption and purchases towards healthier and untaxed foods.

CONCLUSION

Governments already have the optimum tool required to effect changes in consumer behaviour and the food environment.

Estimated changes in free sugar consumption one year after the UK soft drinks industry levy came into force: controlled interrupted time series analysis of the National Diet and Nutrition Survey (2011-2019)

BACKGROUND

The UK soft drinks industry levy (SDIL) was announced in March 2016 and implemented in April 2018, encouraging manufacturers to reduce the sugar content of soft drinks. This is the first study to investigate changes in individual-level consumption of free sugars in relation to the SDIL.

METHODS

We used controlled interrupted time series (2011-2019) to explore changes in the consumption of free sugars in the whole diet and from soft drinks alone 11 months after SDIL implementation in a nationally representative sample of adults (>18 years; n=7999) and children (1.5-19 years; n=7656) drawn from the UK National Diet and Nutrition Survey. Estimates were based on differences between observed data and a counterfactual scenario of no SDIL announcement/implementation. Models included protein consumption (control) and accounted for autocorrelation.

RESULTS

Accounting for trends prior to the SDIL announcement, there were absolute reductions in the daily consumption of free sugars from the whole diet in children and adults of 4.8 g (95% CI 0.6 to 9.1) and 10.9 g (95% CI 7.8 to 13.9), respectively. Comparable reductions in free sugar consumption from drinks alone were 3.0 g (95% CI 0.1 to 5.8) and 5.2 g (95% CI 4.2 to 6.1). The percentage of total dietary energy from free sugars declined over the study period but was not significantly different from the counterfactual.

CONCLUSION

The SDIL led to significant reductions in dietary free sugar consumption in children and adults. Energy from free sugar as a percentage of total energy did not change relative to the counterfactual, which could be due to simultaneous reductions in total energy intake associated with reductions in dietary free sugar.

Advertising and Stocking at Small Retailers: A Sweetened Beverage Excise Tax in Philadelphia

INTRODUCTION

In 2017, Philadelphia enacted a $0.015 per ounce excise tax on SBs that covered both sugar-sweetened beverages and artificially-sweetened beverages, which reduced purchasing and consumption. This study assessed whether the tax also changed beverage advertising or stocking practices that could influence consumer behavior among stores in Philadelphia, Baltimore, and Philadelphia-adjacent counties not subject to the tax.

METHODS

Using a longitudinal difference-in-differences approach, beverage advertising and availability changes were evaluated from 4-month pretax to 6-, 12-, and 24-month post-implementation in small independent stores in Philadelphia (n=34) and Philadelphia-adjacent counties (n=38) versus Baltimore (n=43), a demographically similar city without a tax. Mixed effects models tested whether beverage advertising/availability increased in Philadelphia and surrounding counties after implementation versus Baltimore, included store-level random intercepts, and were stratified by beverage tax status, type, size, and store ZIP code income. Data were collected from 2016 to 2018, and analyses were performed in 2022-2023.

RESULTS

SB advertising increased post-tax in Philadelphia (6 months= +1.04 advertisements/store [95% CI=0.27, 1.80]; 12 months= +1.54 [95% CI=0.57, 2.52]; 24 months= +0.91 [95% CI=0.09, 1.72]) relative to Baltimore. This was driven by increased advertising of sweetened beverages in low-income ZIP codes. Marketing of SBs increased significantly in Philadelphia-adjacent counties relative to Baltimore. Although SB availability in Philadelphia did not change, it increased in surrounding county stores (6 months= +0.20 [95% CI=0.15, 0.25]; 12 months= +0.08 [95% CI=0.03, 0.12]) relative to Baltimore.

CONCLUSIONS

Marketing of SBs, especially in low-income neighborhoods and in surrounding counties, increased following Philadelphia's beverage tax among small, independent retailers. These increases in advertising might have dampened the tax's effect on purchasing behaviors, although estimated effects on sales remained large.

The effects of alcohol tax policies on alcohol consumption and alcohol use disorders in Mainland of China: an interrupted time series analysis from 1961-2019

Background: Overwhelming evidence suggests that increasing alcohol taxes is an effective strategy for curbing alcohol consumption. However, research on the effects of such strategies in low- and middle-income nations is limited.Objective: The aim is to explore the temporal effect of alcohol tax policy in China.Methods: We employ interrupted time series analysis to investigate the temporal effects of tax policy changes on alcohol consumption and related consequences in Mainland China from 1961 to 2019. The study population, the total population of mainland region of China, aged more than 15 years.Results: The results show that the volume tax policy, which was announced in 2000 and implemented in 2001,  led to an immediate reduction in the alcohol consumption (coefficient = -0.429, p < .001). Following the implementation of higher alcohol taxes in 1998 and 2001, the prevalence of alcohol use disorders (AUDs) and related years lived with disability (YLDs) gradually decreased. The relaxation of tax policy in 2006 led to a significant increase in alcohol consumption, both immediately (coefficient = 0.406, p < .001) and in the middle term (coefficient = 0.495, p < .001), as well as contribute to an immediate or medium term significant increase in the prevalence of AUDs (coefficient = 0.038, p = .010; coefficient = 0.032, p < .001) and YLDs (coefficient = 4.363, p = .001; coefficient = 4.226, p < .001).Conclusion: This study demonstrates that changes in alcohol consumption and related consequences (increase or decrease) have followed corresponding changes in alcohol tax policies (easing or tightening), indicating that increasing alcohol taxes can be an effective strategy in China for controlling alcohol consumption and related harms.

Evaluation of the sugar-sweetened beverage tax in Oakland, United States, 2015-2019: A quasi-experimental and cost-effectiveness study

BACKGROUND

While a 2021 federal commission recommended that the United States government levy a sugar-sweetened beverage (SSB) tax to improve diabetes prevention and control efforts, evidence is limited regarding the longer-term impacts of SSB taxes on SSB purchases, health outcomes, costs, and cost-effectiveness. This study estimates the impact and cost-effectiveness of an SSB tax levied in Oakland, California.

METHODS AND FINDINGS

An SSB tax ($0.01/oz) was implemented on July 1, 2017, in Oakland. The main sample of sales data included 11,627 beverage products, 316 stores, and 172,985,767 product-store-month observations. The main analysis, a longitudinal quasi-experimental difference-in-differences approach, compared changes in beverage purchases at stores in Oakland versus Richmond, California (a nontaxed comparator in the same market area) before and 30 months after tax implementation (through December 31, 2019). Additional estimates used synthetic control methods with comparator stores in Los Angeles, California. Estimates were inputted into a closed-cohort microsimulation model to estimate quality-adjusted life years (QALYs) and societal costs (in Oakland) from 6 SSB-associated disease outcomes. In the main analysis, SSB purchases declined by 26.8% (95% CI -39.0 to -14.7, p < 0.001) in Oakland after tax implementation, compared with Richmond. There were no detectable changes in purchases of untaxed beverages or sweet snacks or purchases in border areas surrounding cities. In the synthetic control analysis, declines in SSB purchases were similar to the main analysis (-22.4%, 95% CI -41.7% to -3.0%, p = 0.04). The estimated changes in SSB purchases, when translated into declines in consumption, would be expected to accrue QALYs (94 per 10,000 residents) and significant societal cost savings (>$100,000 per 10,000 residents) over 10 years, with greater gains over a lifetime horizon. Study limitations include a lack of SSB consumption data and use of sales data primarily from chain stores.

CONCLUSIONS

An SSB tax levied in Oakland was associated with a substantial decline in volume of SSBs purchased, an association that was sustained more than 2 years after tax implementation. Our study suggests that SSB taxes are effective policy instruments for improving health and generating significant cost savings for society.

Systematic review on fiscal policy interventions in nutrition

Introduction

Both the World Health Organization and the Lancet Series on Adolescent nutrition recommend that governments adopt fiscal policies to combat diet-related non-communicable diseases (NCDs). However, rigorous, systematic evidence regarding the effects of these interventions is lacking.

Methods

We synthesize the available evidence regarding the impacts of taxes and subsidies that directly affect consumer prices on availability and accessibility of foods and beverages, purchasing behavior, diet quality, health and well-being outcomes as well as considerations for implementation, sustainability and equity.

Results

Our initial search returned 2,113 de-duplicated studies, and ultimately 24 impact evaluations and two systematic reviews met final eligibility criteria and represented unique evaluations. Our meta-analysis of these studies suggests that taxes may decrease purchases of taxed beverages (SMD = -0.14 [95% CI: -0.29 to -0.07], n = 15). Results should be interpreted cautiously due to considerable heterogeneity (Q(14) = 335.19, p = 0.01,τ ^ 2 = 0.03 , I 2 = 95.82%).

Discussion

The evidence base is too limited to draw conclusions about the effects of taxes on beverages and calorie-dense foods on purchases, or on the effects of subsidies on purchasing or diet quality. Overall, the evidence base is inconclusive on whether fiscal policies can meaningfully influence the availability and accessibility of foods and beverages, diet quality, and health outcomes. Policymakers implementing fiscal policies should consider information campaigns on health benefits and health risks associated with certain food and beverage consumption. For taxes, exposure to health information may amplify signaling effects of taxes and reduce avoidance behaviors, such as cross-border shopping. Future evaluations should diversify data sources to better understand impacts on diet and health outcomes.

The effect of soda taxes beyond beverages in Philadelphia

Soda taxes are implemented in several cities across the United States (US) with the aim of reducing sugar intake from sugar sweetened beverages (SSBs). Sugar is linked to obesity and to higher risk of diabetes and cardiovascular conditions. Sodas are targeted with these taxes since they are the main source of sugar for consumers in the US. In presence of potential substitutes, the policy can be undermined by consumers changing their sources of sugar. We examine the heterogeneous effects of the 2017 Philadelphia soda tax on purchases of other items containing sugar. We present an empirical evaluation focusing on the potential substitution toward additional sugary foods in Philadelphia and counties bordering Philadelphia. We find an increase in sugar from purchases of sweetened foods of about 4.3% following the introduction of the tax in Philadelphia and of 3.7% in the neighboring localities. The substitution to sugary foods in Philadelphia offsets 19% of the decrease of sugar from SSBs. Additionally, we find that the substitution offsets 37% of the decrease of sugar from SSBs when including counties bordering Philadelphia. These results suggest that while SSB taxes might be effective at lowering consumption of SSBs, substitution patterns may limit the effectiveness of the tax to reduce overall sugar intake.

Low-income parents' perceptions of a sweetened beverage tax in Philadelphia

Objective: To characterise perceptions of the Philadelphia Beverage Tax among low-income parents. Design: We conducted semi-structured interviews and administered demographic questions via telephone. We based the interview guide and initial codebook on a conceptual model illustrating perceived fairness and effectiveness as essential for successfully adopting food policies. We performed thematic analysis using NVivo 12. Setting: We recruited from a primary care paediatrics clinic in Philadelphia, Pennsylvania from July to August 2020. Participants: Philadelphia parents/caregivers of 2- to 11-year-old children with Medicaid insurance. Results: Participants were predominantly African American (97 %), female (100 %), and had annual household incomes <$50 000 (80 %). Participants were 26- to 72-years old, with an average aged child of 5 years (range 7 months to 20 years). Themes emerged regarding tax perceptions, revenue use and behaviour change due to the tax. Using revenue for highly valued programmes and accountability of city government to use revenue as promised were critical elements in perceptions of tax fairness. Some parents avoided the tax through cross-border shopping and buying drink powders or concentrates, influencing perceptions of tax effectiveness. The tax signalled the health dangers of sweetened beverage consumption to most parents. Conclusion: Our findings bring to light four key takeaways for policymakers designing sweetened beverage taxes. (1) Dedication of tax revenue to programmes highly valued by parents and (2) transparency in revenue spending may improve acceptability. (3) State or national taxes may be more effective at decreasing consumption due to cross-border shopping. (4) Pairing taxes with health promotion campaigns may enhance behaviour change.

Decomposing consumer and producer effects on sugar from beverage purchases after a sugar-based tax on beverages in South Africa

Growing global concern about obesity and diet-related non-communicable diseases has raised interest in fiscal policy as a tool to reduce this disease burden and its social costs, especially excise taxes on sugar-sweetened beverages (SSBs). Of particular interest have been nutrient-based taxes to improve diet quality. These can incentivize producers to reformulate existing products and introduce healthier alternatives into their ranges. In 2018, South Africa adopted a sugar-based tax on SSBs, the Health Promotion Levy (HPL). Early findings suggest that purchases of higher-sugar taxable beverages fell and purchases of no- and lower-sugar beverages increased, alongside significant reductions in the sugar content of overall beverage purchases. However, underlying these changes are consumption shifts as well as product reformulation and changes in producers' product portfolios. Drawing on a household scanner dataset, this study employed a descriptive approach to decompose changes in the sugar content of households' non-alcoholic beverage purchases into producer factors (reformulation and product entry and exit) and consumer factors (product switching and volume changes as a result of price changes, changing preferences, or other factors). We look at these factors as the tax was announced and implemented across a sample of over 3000 South African households, and then by Living Standard Measures (LSM) groups (middle vs. high). The sugar content of beverage purchases fell by 4.9 g/capita/day overall, a 32% decrease. Taken in isolation, consumer switching and volume changes together led to a reduction equivalent to 71% of the total change, while reformulation accounted for a decrease equal to 34% of that change. Middle-LSM households experienced larger reductions than high-LSM households due to larger changes on the consumer side. For both LSM groups, reformulation-led reductions mostly occurred after implementation, and most changes came from taxable beverage purchases. As sugary drink tax designs evolve with broader implementation globally, understanding both supply- and demand-side factors will help to better assess the population and equity potential of these policies.

Sustained Impact of the Philadelphia Beverage Tax on Beverage Prices and Sales Over 2 Years

INTRODUCTION

It is unclear whether changes in beverage price and sales after beverage tax implementation can be sustained long term. This study aims to quantify the changes in beverage prices and sales in large retailers 2 years after the implementation of the 1.5 cents per ounce Philadelphia beverage tax.

METHODS

Data on price and volume sales of beverages and potential food substitutes were collected from 109 supermarkets, 45 mass merchandizers, and 350 pharmacies in Philadelphia, Baltimore (control), and Pennsylvania ZIP codes bordering Philadelphia (to investigate potential cross-border shopping for tax avoidance). Difference-in-differences analyses compared beverage prices and volume sales in the year before tax implementation (2016) to 2 years after (2018). Data were analyzed in 2020-2021.

RESULTS

Difference-in-differences analyses found that after tax implementation, taxed beverage prices in Philadelphia increased by 1.02 cents per ounce (95% CI=0.94, 1.11; 68% pass through), and taxed beverage volume sales in stores decreased by 50% (95% CI=36%, 61%). After accounting for cross-border shopping, taxed beverage volume sales decreased in Philadelphia by 35% in 2018. Volume sales of nontaxed beverages did not change after tax implementation (difference-in-differences=4%, 95% CI= -3%, 12%). Volume sales of nontaxed beverage concentrates increased on average by 34% (95% CI=19%, 51%), but there was no evidence of substitution to high-calorie foods.

CONCLUSIONS

There was a large reduction in taxed beverage volume sales 2 years after Philadelphia tax implementation, even after accounting for cross-border shopping. Increases in nontaxed beverage concentrate sales likely partially offset this decline, but there was no evidence of post-tax food substitution.

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.

The Impact of Sugar-Sweetened Beverage Taxes by Household Income: A Multi-City Comparison of Nielsen Purchasing Data

Due to the role that sugar-sweetened beverages (SSBs) play in the obesity epidemic, SSB taxes have been enacted in the United States in the California cities of Albany, Berkeley, Oakland, and San Francisco, as well as in Boulder, Philadelphia, and Seattle. We pooled five years of Nielsen Consumer Panel and Retail Scanner Data (2014-18) to examine purchasing behaviors in and around these cities that have instituted SSB taxes. We included households that were either subject to the tax during the study period or were in surrounding areas within the same state. The goal was to test for the differential impact of SSB taxes by income level and type of tax. Multivariate analyses of beverage purchases found that (1) there is a dose-response relationship with the size of the SSB tax; (2) the Philadelphia tax, which is the only one that includes low-calorie beverages, is associated with greater reductions in SSB purchases and an increase in bottled water purchase; and (3) approximately 72% of the tax is passed through to consumers, but this does not vary by income level of the household. Few income-related effects were detected. Overall, our findings suggest that the Philadelphia model may be the most effective at encouraging healthy habits in beverage choice.

Impact of the Seattle Sweetened Beverage Tax on substitution to alcoholic beverages

INTRODUCTION

Taxes are increasingly used as a policy tool aimed at reducing consumption of sugar-sweetened beverages (SSBs), given their association with adverse health outcomes including type 2 diabetes, obesity and cardiovascular disease. However, a potential unintended consequence of such a policy could be that the tax induces substitution to alcoholic beverages. The purpose of this study is to examine the impact of the $0.0175 per ounce Seattle, Washington, Sweetened Beverage Tax (SBT) on volume sold of alcoholic beverages.

METHODS

A difference-in-differences estimation approach was used drawing on universal product code-level food store scanner data on beer (N = 1059) and wine (N = 2655) products one-year pre-tax (February-November, 2017) and one and two-years post-tax (February-November, 2018 and 2019) with Portland, Oregon, as the comparison site.

RESULTS

At two-years post-tax implementation, volume sold of beer in Seattle relative to Portland increased by 7% (ratio of incidence rate ratios [RIRR] = 1.07, 95% CI:1.00,1.15), whereas volume sold of wine decreased by 3% (RIRR = 0.97, 95% CI:0.95,1.00). Overall alcohol (both beer and wine) volume sold increased in Seattle compared to Portland by 4% (RIRR = 1.04, 95% CI:1.01,1.07) at one-year post-tax and by 5% (RIRR = 1.05, 95% CI:1.00,1.10) at two-years post-tax. The implied SSB cross-price elasticities of demand for beer and wine, respectively, were calculated to be 0.35 and -0.15.

CONCLUSIONS

There was evidence of substitution to beer following the implementation of the Seattle SSB tax. Continued monitoring of potential unintended outcomes related to the implementation of SSB taxes is needed in future tax evaluations.

Evaluation of Changes in Grams of Sugar Sold After the Implementation of the Seattle Sweetened Beverage Tax

IMPORTANCE

Adults and children routinely exceed recommended intake amounts of added sugars established by dietary guidelines. Taxes are used as a policy tool to reduce demand for sugar-sweetened beverages (SSBs) given consumption-related adverse health outcomes but may induce substitution to other sources of added sugars.

OBJECTIVE

To examine the extent to which changes in grams of sugar sold from taxed beverages may be offset by changes in grams of sugar sold from untaxed beverages, sweets, and stand-alone sugar after the implementation of the Seattle, Washington, Sweetened Beverage Tax (SBT) on January 1, 2018.

DESIGN, SETTING, AND PARTICIPANTS

This study used difference-in-differences analyses to examine changes in grams of sugar sold from taxed and untaxed products in Seattle compared with Portland, Oregon, at year 1 and year 2 post tax. This study used Nielsen scanner data from supermarkets and mass merchandise as well as grocery, drug, convenience, and dollar stores on unit sales and measurements for beverage and food product universal product codes (UPCs) for each site for the pretax period (January 8-December 30, 2017) and the corresponding weeks in year 1 post tax (2018) and in year 2 post tax (2019). Nutritional analyses assessed grams of sugar for each UPC. The analytical balanced sample included 1326 taxed beverage UPCs, 239 untaxed beverage UPCs, 2054 sweets UPCs, and 81 stand-alone sugar UPCs. Statistical analysis was performed from January to August 2021.

EXPOSURES

Implementation of the Seattle SBT.

MAIN OUTCOMES AND MEASURES

Changes in grams of sugar sold from taxed beverages, untaxed beverages, sweets, and stand-alone sugar.

RESULTS

At both year 1 and year 2 post tax in Seattle compared with Portland, grams of sugar sold from taxed beverages decreased 23% (year 2 posttax ratio of incidence rate ratios [RIRR] = 0.77; 95% CI, 0.73-0.80). Sugar sold from untaxed beverages increased at year 1 post tax by 4% (RIRR = 1.04; 95% CI, 1.00-1.07) with no change at year 2 post tax. Sugar sold from sweets increased by 4% at both year 1 and year 2 post tax (year 2 posttax RIRR = 1.04; 95% CI, 1.03-1.06). There were no changes in stand-alone sugar sold.

CONCLUSIONS AND RELEVANCE

This study using difference-in-differences analysis found a net 19% reduction in grams of sugar sold from taxed SSBs at year 2 post tax after accounting for changes in sugar sold from untaxed beverages, sweets, and stand-alone sugar. These results suggest that SSB taxes may effectively yield permanent reductions in added sugars sold from SSBs in food stores.

The Impact of Seattle's Sugar-Sweetened Beverage Tax on Substitution to Sweets and Salty Snacks

BACKGROUND

Sugar-sweetened beverage (SSB) taxes may have broad effects on purchases of untaxed foods, and substitution of SSBs with untaxed sweets and/or salty snacks could offset the intended dietary and health effects of these policies.

OBJECTIVES

To test whether there were changes in sales and calories sold for untaxed foods in response to the SSB tax in Seattle, Washington, at 12 and 24 months post-tax implementation.

METHODS

On 1 January 2018, the City of Seattle levied a 1.75 cents per ounce excise tax on distributors selling targeted SSBs. We utilized universal product code-level store scanner data and employed a difference-in-differences approach to assess the impacts of the tax on the changes in 1) sales of sweets and salty snacks; and 2) total calories sold for sweets in Seattle relative to changes in its comparison site of Portland, Oregon, at 12 and 24 months post-tax.

RESULTS

In the 12 months post-tax, sales of sweets increased by 4% [ratio of incidence rate ratios (RIRR), 1.04; 95% CI, 1.03-1.05] in Seattle relative to the changes in Portland; at 24 months post-tax, sweet sales increased by 6% (RIRR, 1.06; 95% CI, 1.05-1.07) relative to the pretax period. There was no significant change in sales of salty snacks at 12 months (RIRR, 1.00; 95% CI, 0.99-1.01) or 24 months (RIRR, 1.00; 95% CI, 0.98-1.02) post-tax. Total calories sold for sweets increased by 3% (RIRR, 1.03; 95% CI, 1.02-1.05) in Seattle compared with Portland at 12 months post-tax and by 4% (RIRR, 1.04; 95% CI, 1.02-1.05) at 24 months after implementation.

CONCLUSIONS

There was modest substitution of SSBs for sweets in Seattle following tax implementation. However, this increase in sales and calories sold is not likely to offset previously identified tax-related reductions in the demand for taxed beverages in Seattle. Thus, SSB taxes are a promising policy tool to reduce caloric intake in the United States.

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.