Are Sugar-Sweetened Beverage Information Labels Well-Targeted

NCT ID: NCT05038163

Last Updated: 2024-12-11

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 5845 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2021-10-18
• Study Completion Date: 2021-12-22

Brief Summary

We will study the extent to which soft drink information labels -- designed to curb unhealthy consumption -- are well-targeted to the most biased consumers.The study team will deploy novel methods for evaluating the targeting properties of information labels via an incentive-compatible online shopping experiment. At a high-level, we will ask whether the treatment effects of the information labels are concentrated on individuals with the biggest self-control problems and with the least knowledge of nutrition. We will first use the methodology from Allcott et al. (2019) to estimate the internality for each participant. We will then have participants make shopping decisions for soft drinks, first absent any information labels and then, for those not in the control group, in the presence of an information label. The within-subject design of the soft drinks experiment will allow us to estimate how the effects of the labels covary with consumers' internalities, and thus to determine whether the labels are well-targeted.

Detailed Description

We will use online ads to recruit people who are shopping online for soda, and direct them to a two-stage online Qualtrics experiment. In the first stage (Part I), we will elicit subjects' nutritional literacy and self-control for resisting sugary drinks, following the methodology of Allcott et al. (2019). Allcott et al. (2019) show that these two measures explain 31% of sugary drinks consumption in a nationally-representative sample of approximately 20,000 households, after controlling for detailed demographic information and elicitations of "tastes" for various types of drinks. Additionally, Allcott et al. (2019) demonstrate how these measures can be used to provide an estimate of over-consumption of sugary drinks at the individual level. Consequently, the first stage allows us to obtain estimates of the internality.

A week later, we will recruit participants in the first stage to participate in the second stage of the experiment (Part II). We create a time delay to minimize the potential effect of the first-stage questions on the second-stage choices. In the second stage, we will first ask participants to select their three favorite sugary drinks from a list. We will then ask participants to make an initial set of choices between those drinks and sugar-free alternatives (e.g., Seagram's Ginger Ale versus 365 Ginger) at various relative prices. Specifically, we will elicit their willingness to pay using a multiple price list, as is standard in the behavioral economics literature, where consumers answer a series of questions about whether they would prefer to buy a sugar-sweetened beverage at price X or a sugar-free alternative at price Y. Choices will be incentive-compatible: for each consumer we will honor their choice in a randomly selected decision (i.e., we will purchase the chosen package of soft drinks for them plus award them any additional money associated with that choice).

Following an initial set of choices, we will ask subjects to choose again. In this second set of choices, we will randomize whether participants see the soft drink options paired with an information label. We will also randomize the types of labels, including: (i) an inflated nutrition label that draws attention to the differences in calories and sugar content, (ii) the stoplight warning label developed by Grummon, Hall, et al. (2019), and (iii) a graphic warning label developed by Donnelly et al. (2018). The control group will instead make the same choices without seeing any label. Leveraging the within-subject nature of design, we will then estimate how well-targeted each information label is by estimating how the subjects' internalities covary with their changes in the prices at which they are willing to buy soft drinks after seeing the information label.

Conditions

Soft Drink Consumption; Sugar-sweetened Beverages; Information Labels

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: PREVENTION
• Blinding Strategy: NONE

Study Groups

Control Arm

In Part II of the experiment, subjects are not presented with nutrition or warning labels when choosing between beverages.

Group Type: NO_INTERVENTION

No interventions assigned to this group

Nutrition Labels Arm

In Part II of the experiment, subjects are shown enlarged nutrition labels when choosing between beverages.

Group Type: EXPERIMENTAL

Nutrition Facts

Intervention Type: OTHER

The nutritional information label for each beverage is enlarged.

Text Warning Labels Arm

In Part II of the experiment, subjects are shown a warning message about the health risks of sugary beverages when choosing between beverages.

Group Type: EXPERIMENTAL

Text Warning

Intervention Type: OTHER

The health risks of sugary beverages are communicated to subjects using words/text and simple images.

Graphic Warning Labels Arm

In Part II of the experiment, subjects are shown a graphic warning message about the health risks of sugary beverages when choosing between beverages. The message, for example, could include photos of tooth decay and other negative health outcomes.

Group Type: EXPERIMENTAL

Graphic Warning

Intervention Type: OTHER

The health risks of sugary beverages are communicated to subjects using a combination of words/text and graphic images/photographs.

Interventions

Nutrition Facts

The nutritional information label for each beverage is enlarged.

Intervention Type: OTHER

Text Warning

The health risks of sugary beverages are communicated to subjects using words/text and simple images.

Intervention Type: OTHER

Graphic Warning

The health risks of sugary beverages are communicated to subjects using a combination of words/text and graphic images/photographs.

Intervention Type: OTHER

Other Intervention Names

Stoplight Warning

Eligibility Criteria

Inclusion Criteria

• US resident
• Shopping online for sugar-sweetened beverages

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

University of California, Berkeley

OTHER

Sponsor Role: collaborator

National Institute on Aging (NIA)

NIH

Sponsor Role: collaborator

National Bureau of Economic Research, Inc.

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Dmitry Taubinsky, PhD

Role: PRINCIPAL_INVESTIGATOR

UC Berkeley and NBER

Locations

University of California, Berkeley

Berkeley, California, United States

Countries

United States

References

Allcott H, Lockwood BB, Taubinsky D. Regressive Sin Taxes, with an Application to the Optimal Soda Tax. Quarterly Journal of Economics. 2019; 134(3).

Reference Type: BACKGROUND

Grummon AH, Hall MG, Taillie LS, Brewer NT. How should sugar-sweetened beverage health warnings be designed? A randomized experiment. Prev Med. 2019 Apr;121:158-166. doi: 10.1016/j.ypmed.2019.02.010. Epub 2019 Feb 14.

Reference Type: BACKGROUND

PMID: 30772370 (View on PubMed)

Donnelly GE, Zatz LY, Svirsky D, John LK. The Effect of Graphic Warnings on Sugary-Drink Purchasing. Psychol Sci. 2018 Aug;29(8):1321-1333. doi: 10.1177/0956797618766361. Epub 2018 Jun 18.

Reference Type: BACKGROUND

PMID: 29912624 (View on PubMed)

Provided Documents

Document Type: Study Protocol

View Document

Document Type: Statistical Analysis Plan

View Document

Document Type: Informed Consent Form

View Document

Other Identifiers

P30AG034532

Identifier Type: NIH

Identifier Source: secondary_id

View Link

2020-08-13558

Identifier Type: -

Identifier Source: org_study_id