The effects of an abrupt increase in taxes on candy and soda in Norway: an observational study of retail sales

Abstract

Background Fiscal policies are used to promote a healthier diet; however, there is still a call for real-world evaluations of taxes on unhealthy foods and beverages. We aimed to evaluate the effect of an abrupt increase, of respectively 80 and 40%, in the excising Norwegian taxes on candy and beverages on volume sales of candy and soda. We expected sales to fall. Methods We analyzed electronic point of sale data covering approximately 98% of volume sales of grocery stores in Norway. In two pre-registered models with weekly (log-)sales of taxed candy and soda from 3884 individual stores, we modeled the difference between the jump (discontinuity) in the trend around the time of the increase in taxes and the corresponding jump in the trend in a control season from the previous years (Model 1). In addition, we modeled the difference between the intervention and the control season in their changes in average sales (Model 2). Results Model 1 showed a 6.1% (one-sided 95% CI: not applicable (NA), 23.4, p-value = 0.26) increase and a − 3.9% (95% CI: NA, 4.9, p-value = 0.23) reduction in the differences in the jump in the trends, for candy and soda, respectively. The second model showed a relative decrease of − 4.9% (95% CI: NA, 1.0, p-value = 0.08) in the average sales of candy and an increase of 1.5% (95% CI: NA, 5.0, p-value = 0.24) in sales of soda. Supplementary analyses suggested that the results were sensitive to clustering on the time dimension. Conclusions When using two different quasi-experimental designs to model changes in volume sales of taxed candy and soda, we were not able to detect reductions in sales that coincided with an increase in the taxes. Variation across time makes it difficult to detect potentially small changes in sales even when using an entire country’s worth of sales data on the level of individual stores. We speculate that the tax increases were too modest to affect the prices to alter sales sufficiently.

Systematic review on fiscal policy interventions in nutrition

“…In Mexico, Aguilar Esteva et al (17) find no effect on total calories purchased (g = −0.04 [95% CI: −0.09 to 0.00]). In Norway, Øvrebø et al (33) find no change in the sale of candy (g = 0.01 [95% CI: −0.06 to 0.07]). When considered jointly, these results suggest no change in the purchasing of sugary foods (µ = − 0.02 [95% CI: −0.07 to 0.02]; p = 0.34; Supplementary material 5, Figure 5).…”

Novel Insights from Stratified Cost-Effectiveness Analysis of Sugar-Sweetened Beverage Tax Policy in Norway: A Comparative Modeling Study

“…The average price of SSBs in 2017 was roughly NOK 22.15 per liter in Norway [28], so the expected percentage change in the price of domestic SSBs (…”

“…Cross-border shopping is popular among Norwegians because of significant and persistent price differences in neighboring countries like Sweden [28,33]. Soda was 3 This graph is adapted from Fig 1.…”

“…It was found that a high SSB tax in Norway could make Norwegian producers less competitive on market and its effect on public health might not be much significant at all. Besides, an observational study of retail sales in Norway indicated that an abrupt increase in taxes on candy and soda in 2018 was too modest to sufficiently influence the public consumption of SSBs [28]. As we see, existing studies focused on empirical evidence in the short time horizon without considering the latently "delayed" policy effects in the future.…”

Do taxes on unhealthy foods and beverages influence food purchases?

“…Appropriate rates of taxation are likely to be influenced by contextual and political factors, and are likely to vary across products and regions. For example, while an 8% tax on nonessential energy-dense foods is reported to have reduced purchase of taxed foods in Mexico [34,35], a tax of a similar rate on confectionery in Norway had an uncertain effect on consumer behaviour [49]. However, these taxes are modest compared to some recently implemented taxes.…”