Sugary-drink sales rose overall but fell per person
In Mexico, total sales after the tax exceeded the prior average. Adjusting for population and the economy, the model estimated a per-person decrease.
The key idea
When comparing sales before and after a policy, adjusting per person and for context can change the interpretation.
The study, in plain language
Researchers analyzed monthly manufacturer sales in Mexico from 2007 to 2015: 108 months of data. They compared years after the tax with the pre-tax period and adjusted their models for population, season, and economic activity.
Total sales of taxed beverages were higher in the two years after the tax. The adjusted model, however, estimated lower per-person sales, while water sales increased. The contrast shows why it matters how many people lived in the country and what else changed when interpreting the same period. Limitations: categories included some untaxed drinks, sales included exports and excluded imports, and without a comparison group the tax cannot be separated from other changes.
What they found
- In the two years after the tax, total sales of those beverages exceeded the prior average.
- Adjusting for population, season, and the economy, the model estimated lower sales per person.
- With the same adjustment, water sales per person increased.
Something to think about
When you see a public-policy figure, is it a total, a per-person number, or a number adjusted for context? Check which it is before comparing it with another.
How they studied it
Researchers observationally analyzed 108 monthly manufacturer sales figures in Mexico from January 2007 through December 2015. Their models accounted for season, population, and economic activity. This was a time comparison of national sales without a control group. The category included some untaxed drinks and did not cover all bottled-water sales.
What the study cannot show
- There was no experimental assignment, and other national changes may have contributed to the observed pattern.
- Categories analyzed included some untaxed beverages. Manufacturer sales included exports and excluded imports, and did not measure individual intake.
The original study
Beverages Sales in Mexico before and after Implementation of a Sugar Sweetened Beverage Tax
Source under CC BY 4.0. English adaptation and explanation by PaperFlow, with AI assistance. The text has been reorganized for a general audience; it is not the complete paper and does not imply endorsement by its authors.
One study alone does not represent a field's consensus. Educational content does not replace professional advice. Report a possible error.
