None listed
Conditions
Brief summary
This pilot randomised controlled study aims to examine the effects of a sugar-sweetened beverage (SSB) tax or SSB tax information or a combination of both on purchases and on consumer perceptions using the recently developed New Zealand Virtual Supermarket. The New Zealand Virtual Supermarket is a three-dimensional software application that has been designed in the image of a real New Zealand supermarket. SSB taxes have been proposed as a method to reduce soft drink consumption (and subsequently reduce calorie intake) and could therefore help to tackle the growing obesity epidemic. Evidence on the effectiveness of soft drink taxes is however very limited and has largely been restricted to modelling studies which are not able to explore how information and knowledge about such a tax (referred to as price salience in the economic literature) would mediate changes in consumption. Moreover, such studies give limited insight in cross-price elasticity and substitution effects (e.g., it has been suggested that increased SSB taxes might result in an increased alcohol intake). Before taxes are implemented on a large scale, it is important to gain more insight into these effects and examine the best design of the tax for public health outcomes. Therefore this study aims to: 1. To examine the differences in SSB purchases between groups of participants exposed to different SSB tax and information scenarios within the Virtual Supermarket. 2. To obtain participant feedback on perceptions of the SSB tax and their intended response to the tax. Participants (recruited from the general adult NZ population) will be randomized to one of seven conditions (pricing and/or information conditions or control) and will be asked to conduct a weekly household shop in the Virtual Supermarket. The Virtual Supermarket is a 3-dimensional software application designed in the image of a real supermarket. It models a representative product selection of food items that can normally be found in a NZ supermarket, including a wide range of soft drinks. Participants will be provided with a link to this software and can complete this study from their home computer or any computer with internet access. This pilot trial will be designed to provide an optimal level of information on the potential effectiveness of different tax and information combinations. We anticipate that this trial will inform the design of a larger trial by identifying the interventions with the largest potential for public health.
Interventions
All participants will be asked to conduct a typical weekly shop in the Virtual Supermarket, which is a three-dimensional software application that has been designed in the image of a real New Zealand supermarket. Upon registration, participants will be blindly randomised to one of the following:
- control
- a 20% tax on sugar sweetened beverages and no information about the tax
- a 20% tax on sugar sweetened beverages and information in the form of a newspaper article about the tax prior to the
All participants will be asked to conduct a typical weekly shop in the Virtual Supermarket, which is a three-dimensional software application that has been designed in the image of a real New Zealand supermarket. Upon registration, participants will be blindly randomised to one of the following: - control - a 20% tax on sugar sweetened beverages and no information about the tax - a 20% tax on sugar sweetened beverages and information in the form of a newspaper article about the tax prior to the virtual shop - a 20% tax on sugar-sweetened beverages and information in the form of in-store labels on taxed products - a 20% tax on sugar-sweetened beverages and information in the form of both in-store labels on taxed products and a newspaper article about the tax prior to the virtual shop - no tax on sugar sweetened beverages and information in the form of a newspaper article about the tax prior to the virtual shop - no tax on sugar-sweetened beverages and information in the form of in-store labels on "taxed" products Participants randomised to an information condition but no tax will be falsely informed that a tax has been put in place (e.g. taxed label on SSB but no price change)
Sponsors
University of Auckland
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Prevention
Masking
Blinded (masking used) (Subject)
Eligibility
Sex/Gender
All
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
Adult (over 18 years) Key responsible person in the household for grocery shopping Speaks and reads English Has access to a computer and internet Has an email address
Exclusion criteria
Participants will be excluded if another member of the household is taking part in the study
Outcome results
None listed