From Convenience to Conscience: A Field Experiment on Influencing Local and Eco-Friendly Milk Purchases through Habit Formation

Last registered on March 25, 2024
View Trial History

Pre-Trial

Trial Information

General Information

Title
From Convenience to Conscience: A Field Experiment on Influencing Local and Eco-Friendly Milk Purchases through Habit Formation
RCT ID
AEARCTR-0013225
Initial registration date
March 20, 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
March 25, 2024, 11:19 AM EDT

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

Locations

There is information in this trial unavailable to the public. Use the button below to request access.

Request Information

Primary Investigator

Name
Shuoli Zhao
Affiliation
University of Kentucky
Contact Primary Investigator

Other Primary Investigator(s)

PI Name
Tim Woods
PI Affiliation
University of Kentucky
Contact Investigator

Additional Trial Information

Status
In development
Start date
2024-03-01
End date
2024-08-31
Keywords
Agriculture, Behavior, Environment & Energy
Additional Keywords
JEL code(s)
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
Consumer interest in eco-friendly and local food sources is growing, leading to the adoption of glass bottles for taste preservation, recyclability, and reusability. However, the logistics of bottle return pose challenges for persistent demand. This study investigates the impact of monetary incentives on glass-bottled milk purchases and their potential to foster long-term habit changes. Partnering with a grocery co-op with more than 10,000 members, we implemented a randomized experiment at the household level where treated members received coupons at purchase, others upon bottle return, and a control group received no incentive. We hypothesize increased sales for incentivized groups with higher return rates when coupons are tied to returns and overall habit formation in treatment groups. This study offers valuable insights into whether habit formation drives lasting shifts toward sustainable dairy choices.
External Link(s)

Registration Citation

Citation
Woods, Tim and Shuoli Zhao. 2024. "From Convenience to Conscience: A Field Experiment on Influencing Local and Eco-Friendly Milk Purchases through Habit Formation ." AEA RCT Registry. March 25. https://doi.org/10.1257/rct.13225-1.0
Sponsors & Partners

There is information in this trial unavailable to the public. Use the button below to request access.

Request Information
Experimental Details

Interventions

Intervention(s)
Intervention Start Date
2024-04-01
Intervention End Date
2024-05-05

Primary Outcomes

Primary Outcomes (end points)
Key outcome variables include purchases of glass-bottled milk, returns of glass bottles, and use of coupons.
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
This experiment utilizes randomly selected members from a grocery co-op, divided into three groups: Normal Consumer (NC), Purchase Consumer (PC), and Deposit Consumer (DC). The NC group serves as the control with no incentives. The PC group receives a coupon discount when purchasing glass-bottled milk, while the DC group receives their discount as a monetary return upon returning the bottle. The study has four phases: a five-week baseline to establish normal buying patterns, a five-week treatment period where coupons are active, a five-week post-observation phase immediately after coupons expire, and a final five-week long-term observation period. This design investigates the impact of different coupon incentives on eco-friendly and local milk purchases and the potential for lasting habit formation. It also helps distinguish between the effects of the initial purchase discount and the bottle return discount.
Experimental Design Details
Not available
Randomization Method
Active co-op members are randomized in Microsoft Excel using a randomization add-on
Randomization Unit
individual
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
N/A
Sample size: planned number of observations
4,500 Grocery Co-op Members
Sample size (or number of clusters) by treatment arms
1,500 individuals per treatment for the two coupon treatments and one control
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Supporting Documents and Materials
IRB

Institutional Review Boards (IRBs)

IRB Name
University of Kentucky
IRB Approval Date
2024-03-14
IRB Approval Number
93576
Analysis Plan