Changes in Beverage Marketing at Stores Following the Oakland Sugar-Sweetened Beverage Tax.

INTRODUCTION

In July 2017, Oakland, California implemented a 1 cent/ounce sugar-sweetened beverage tax. This study examined changes in store marketing practices-advertising and price promotions-for sugar-sweetened beverages, artificially sweetened beverages, and unsweetened beverages following the introduction of the tax.

METHODS

The study employed a quasi-experimental research design and included Oakland as the intervention site and Sacramento, California as a comparison site. Based on data collected pretax (May-June 2017), 6 months post-tax (January 2018), and 12 months post-tax (June 2018) at 249 stores across the 2 sites, exterior and interior advertising for 4 taxed sugar-sweetened beverage subtypes and 6 untaxed artificially sweetened and unsweetened beverage subtypes, as well as price promotions for 59 specific taxed products and 69 untaxed products were examined. In 2019, difference-in-differences logistic regressions estimated pre-post changes in Oakland relative to Sacramento.

RESULTS

At 6 months post-tax, the odds of sugar-sweetened beverage price promotions fell 50% in Oakland but only 22% in Sacramento. Price promotions for regular soda in particular declined in Oakland post-tax, by 47% at 6 months and 39% at 12 months (versus no change in Sacramento). Moreover, the odds of artificially sweetened beverage price promotions fell by a similar magnitude as sugar-sweetened beverages in Oakland, 55% at 6 months and 53% at 12 months, which differed significantly from Sacramento. No significant post-tax changes were found in sugar-sweetened or artificially sweetened beverage exterior or interior advertising.

CONCLUSIONS

Rather than increasing marketing, retailers and manufacturers may have tried to offset revenue losses by reducing price promotions for sugar-sweetened beverages, particularly regular soda, and artificially sweetened beverages.