The Impact of Price Incentives and Behavioral Nudges on Plant-Based Food Consumption: Evidence from a Nationwide Randomized Field Experiment

Last registered on August 06, 2024

Pre-Trial

Trial Information

General Information

Title
The Impact of Price Incentives and Behavioral Nudges on Plant-Based Food Consumption: Evidence from a Nationwide Randomized Field Experiment
RCT ID
AEARCTR-0014064
Initial registration date
July 28, 2024

Initial registration date is when the trial was registered.

It corresponds to when the registration was submitted to the Registry to be reviewed for publication.

First published
August 06, 2024, 10:51 AM EDT

First published corresponds to when the trial was first made public on the Registry after being reviewed.

Locations

Region

Primary Investigator

Affiliation
Policy Research Institute, Ministry of Agriculture, Forestry and Fisheries, Japan

Other Primary Investigator(s)

PI Affiliation
Yamagata University

Additional Trial Information

Status
In development
Start date
2024-08-13
End date
2025-01-31
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
This study aims to investigate the effectiveness of "behavioral insights" and "monetary incentives" in promoting consumers' selection of plant-based foods (PBF), which are expected to address food issues such as the protein crisis and serve as a countermeasure against global warming. The research will be conducted through a randomized field experiment using purchase data collected via a smartphone household account book application. The data collected in this study is characterized by its ability to track individuals across stores, business formats, and product categories, allowing for a high-resolution capture of daily purchasing behavior. Moreover, this experiment is a "Natural Field Experiment" (NFE) where participants are unaware of their involvement, which is particularly advantageous in naturally observing consumers' daily food choices. This research aims to elucidate the following two points: (1) Using high-resolution data, we will rigorously determine the impact of consumer appeals utilizing behavioral insights, such as nudges, on PBF selection, including long-term effects. (2) Based on previous studies suggesting that information provision alone is insufficient to induce behavioral changes in food selection and that a combination with monetary incentives is crucial, we will examine the effect of monetary incentives (specifically, point cashback) on PBF selection, as well as the combined effect of nudges and monetary incentives. This study will contribute to our understanding of effective strategies to promote plant-based food consumption, addressing both environmental and nutritional challenges.
External Link(s)

Registration Citation

Citation
Kyoi, Shinsuke and Hiroki SASAKI. 2024. "The Impact of Price Incentives and Behavioral Nudges on Plant-Based Food Consumption: Evidence from a Nationwide Randomized Field Experiment." AEA RCT Registry. August 06. https://doi.org/10.1257/rct.14064-1.0
Sponsors & Partners

Sponsors

Experimental Details

Interventions

Intervention(s)
The study targets receipt-buying and shopping app users and divides them into one control group and seven intervention groups. Among the vast amount of purchasing data, the primary interest of the researchers lies in the purchasing data related to plant-based food (especially plant-based meat). The interventions are implemented as follows:
The control group collects natural purchasing data.

Treatment groups 1 to 3 receive information provision:
- Treatment Group 1 receives information on the environmental impact of PBF (Plant-Based Food)
- Treatment Group 2 receives information on the health impacts of PBF
- Treatment Group 3 receives feedback on their purchase history based on the past six months of PBF purchase data before the intervention

Treatment groups 4 to 7 receive financial incentives for purchasing PBF. In these groups, users who purchase PBF and upload their receipts will be awarded points. Points, equivalent to about 10% of the product price, will be awarded and can be used as cash:
- Treatment Group 4 receives only financial incentives
- Treatment Group 5 receives environmental information plus financial incentives
- Treatment Group 6 receives health information plus financial incentives
- Treatment Group 7 receives feedback on purchase history plus financial incentives

Intervention (Hidden)
The information provided to each group is as follows.

1. A general explanation common to all groups, except the control group.
"Plant-based Foods" and "What is Plant-based Meat"
"In recent years, reflecting diverse consumer preferences, there has been an increase in foods that use plant-derived ingredients instead of animal-derived ingredients (plant-based foods). The characteristic of plant-based foods is that they are made to resemble livestock and seafood products using these plant-derived ingredients. So far, processed foods that serve as alternatives to "meat," "eggs," "milk," "butter," and "cheese" have been manufactured and sold using ingredients such as soybeans and wheat.
You may have particularly noticed plant-based meat that recreates the taste and texture of meat in supermarkets and other stores. While the main ingredient of plant-based meat is soy, there are also versions made from wheat, peas, and broad beans. Here, we will use the general term "plant-based meat" to refer to meat made from plant-derived ingredients."


2. Treatment Group 1&5 (environmental information):
"Among the total greenhouse gas emissions related to diet, meat products account for the highest proportion. On the other hand, plant-based meat is known to have a lower environmental impact compared to conventional livestock products.
According to the Food and Agriculture Organization of the United Nations (FAO), the livestock industry is responsible for 14.5% of human-induced greenhouse gas emissions. In Japan, greenhouse gases from cattle burps and livestock excrement account for about 30% of the total emissions from the agriculture and forestry sector. If not properly treated before discharge, manure and wastewater from the livestock industry can cause pollution in rivers and other water bodies. Furthermore, water consumption by livestock is also debated as a significant environmental burden. To produce the same 1kg of product, beef requires eight times more water than soybeans.
While we cannot reduce our environmental impact to zero as long as we live, it is necessary for each individual to be conscious of how the act of "eating" is connected to environmental issues. We need to skillfully combine animal-based meat with plant-based foods in our diets."

3. Treatment Group 2&6 (Health information):
"Due to the growing awareness of health in dietary habits, plant-based meat (PBF) has been gaining attention in recent years. Plant-based meat is known for its nutritional benefits, such as being lower in calories and providing high-quality protein and dietary fiber compared to animal meat. Recently, 37 researchers from 16 countries published a study in the British medical journal "The Lancet," pointing out that excessive consumption of red meat (such as beef, pork, and lamb) poses health risks and proposed halving global red meat consumption. There are also studies specific to the Japanese population. Research by the National Cancer Center, which tracked approximately 70,000 Japanese people over an average of 18 years, found that those who frequently consume plant-based protein maintain a healthier lifestyle.
Thus, it is scientifically evident that replacing red meat with plant-based protein reduces disease risk. While animal meat is a good source of high-quality protein, overconsumption carries risks. It is important to skillfully combine animal meat and plant-based foods in your diet."

4. Treatment Group 3&7 (Purchase history feedback):
"It appears that over the past six months (from X month X day to X month X day), you have been purchasing plant-based meat (and uploading related receipts).
We encourage you to continue exploring such foods that cater to the diverse needs of consumers."
Intervention Start Date
2024-08-13
Intervention End Date
2024-09-16

Primary Outcomes

Primary Outcomes (end points)
Extract the purchase history (amount, quantity, and average unit price) related to the following product data from all purchase records.
Data collection items:
・Plant-Based Foods (PBF) (Soy Meat)
・Fresh Vegetables and Fruits
・Meat: Beef, Pork, Chicken, Processed Meat
・Seafood
・The Other Food Expenditure






Primary Outcomes (explanation)
The primary objective is to observe the impact of the intervention on PBF purchasing behavior. Additionally, the observation will include the impact on purchasing behavior for other food items (i.e., spillover effects).

Secondary Outcomes

Secondary Outcomes (end points)
One month after the intervention, a survey will be conducted to ask about the consumption status of PBF and meat, impressions in terms of price, health, nutrition, and environmental impact, and attitudes towards switching from meat to PBF. These responses will constitute the secondary outcomes.
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
This study analyzes the impact of nudges, price incentives, and the combination of both on the purchasing behavior of users of the largest receipt-buying and shopping app in Japan (6 million users). App users upload their purchase receipts daily, with any receipt being bought for 10 JPY. There are active and inactive users, but for this experiment, participants will be randomly selected from among the active users who upload receipts daily. Each group will consist of 400 app users, and since they are unaware of their participation, this experiment is a Natural Field Experiment. As explained above, they will be divided into a control group and seven treatment groups.

For Treatment Groups 1 to 3, a simple questionnaire introducing basic information about PBF (Plant-Based Food) and related nudges will be sent via the app on August 13, the start of the experiment. At this point, attribute information will also be collected. This is the method of information provision. Although it is difficult to determine whether users have viewed the information only through push notifications on the app, completion of the questionnaire will be considered confirmation that they have reviewed the provided information. Subsequently, purchasing data will be collected for approximately five months.

For the groups receiving financial incentives, an icon will be displayed in the app on August 13, indicating that users can earn additional points for purchasing plant-based meat. For users in Treatment groups 5 to 7, additional information on "environment," "health," and "purchase history" respectively is displayed on the app screen. Clicking this icon will be taken as recognition of the additional points offer for PBF purchases. Purchasing data will then be collected by the end of January. The campaign offering additional points for purchasing PBF (Plant-Based Food) will end approximately one month after its introduction. The purpose of this is to observe whether the purchasing habits formed before the incentive period continue after the financial incentives are removed.

In addition, a questionnaire will be administered to both the control and treatment groups approximately one month after the intervention, asking about their thoughts on plant-based meat and their purchasing intentions.
Experimental Design Details
Randomization Method
randomization done by the shopping app developper
Randomization Unit
individual revel
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
N/A
Sample size: planned number of observations
3,200 individuals
Sample size (or number of clusters) by treatment arms
We will set up a control group of 400 people and treatment groups 1 through 7 with 400 people each. Therefore, we will collect purchase data from a total of 3,200 individuals.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
We present the results of prior power calculations for each of the outcome variables mentioned above. We set α=0.05 and β=0.2. A prior power analysis (effect size: 0.2, assuming a small effect size, significance level: 0.05, Power (1-β err prob): 0.8) calculated the required sample size to be 394 samples per group. Therefore, for 8 groups, 3200 individuals would need to be secured.
IRB

Institutional Review Boards (IRBs)

IRB Name
Policy Research Institute, Ministry of Agriculture, Forestry and Fisheries, Japan
IRB Approval Date
2024-07-16
IRB Approval Number
2024FY-01

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Intervention

Is the intervention completed?
No
Data Collection Complete
Data Publication

Data Publication

Is public data available?
No

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