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The ethical consumer: Do consumers care more about social or environmental sustainability?
Last registered on November 20, 2019

Pre-Trial

Trial Information
General Information
Title
The ethical consumer: Do consumers care more about social or environmental sustainability?
RCT ID
AEARCTR-0005066
Initial registration date
November 20, 2019
Last updated
November 20, 2019 2:54 PM EST
Location(s)

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Primary Investigator
Affiliation
University of Cologne
Other Primary Investigator(s)
PI Affiliation
University of Cologne
PI Affiliation
University of Cologne
PI Affiliation
Additional Trial Information
Status
In development
Start date
2019-11-21
End date
2020-02-29
Secondary IDs
Abstract
In a previous study, we conducted a randomized experiment to test whether consumers’ willingness to accept, elicited in an incentivized auction (BDM), increases when they are informed that a product is produced in a socially and environmentally sustainable way. We find a significant increase. However, our design does not allow us to disentangle if the increase is driven by the social sustainability-related aspects of the environmental sustainability-related aspects of the production. In this project, we replicate the methodological approach of our previous study but alter the information consumers receive. To be able to answer the question if consumers care more about the social or environmental impact of the production of goods, we either inform them about social sustainability-related aspects or environmental sustainability-related aspects of the production, but not about both simultaneously.
External Link(s)
Registration Citation
Citation
Conrads, Julian et al. 2019. "The ethical consumer: Do consumers care more about social or environmental sustainability?." AEA RCT Registry. November 20. https://doi.org/10.1257/rct.5066-1.0.
Experimental Details
Interventions
Intervention(s)
We create variation by handing out different informational sheets about the backpack. The sheets contain a picture of the backpack on the left. On the right, participants in the SCL treatment find the following text with three bullet points:
The backpack is characterized by
• high functionality (e.g. expandable from 26 to 33 liters, padded laptop compartment, 2 accesses to main compartment: rolltop system and circulating zipper),
• outstanding wearing comfort (e.g. ergonomic shoulder straps, padded back section, removable and adjustable chest strap),
• water-repellence.
• a socially compatible production, i.e. regular auditing of working conditions of the backpack production by the independent third party Fair Wear Foundation (including occupational safety reviews, employee training and no child labor), and long and transparent partnership with suppliers

In the ECO treatment, participants find the following text with three bullet points:
• high functionality (e.g. expandable from 26 to 33 liters, padded laptop compartment, 2 accesses to main compartment: rolltop system and circulating zipper),
• outstanding wearing comfort (e.g. ergonomic shoulder straps, padded back section, removable and adjustable chest strap),
• water-repellence.
• an ecologically compatible production (e.g. fabrics made from 100% recycled PET bottles, backpack free of PFCs harmful to the environment and health and continuous reduction of negative environmental impacts in production as certified by the independent third party bluesign)
Intervention Start Date
2019-11-21
Intervention End Date
2020-02-29
Primary Outcomes
Primary Outcomes (end points)
Difference in willingness to accept
Primary Outcomes (explanation)
See experimental details
Secondary Outcomes
Secondary Outcomes (end points)
Secondary Outcomes (explanation)
Experimental Design
Experimental Design
We investigate if consumers value a socially or an environmentally sustainable production of goods more by measuring the increase in their willingness to accept (WTA) for backpacks when they are either only informed about the social sustainability-related aspects in the production or only about the environmental sustainability-related aspects. WTA are elicited by using an Becker-DeGroot-Marschak auction (BDM) (Becker, DeGroot, & Marschak, 1964). More precisely, participants are given a backpack that they can immediately sell back in two BDM auction rounds. After inspecting the backpack, participants state their minimum selling price in a first pre-intervention auction round. Then, they are given information about functionality and wearing comfort of the backpack, e.g., being water-repellent. In addition and depending on the treatment, participants either receive information about social (SCL) or about ecological (ECO) sustainability. In a second post-intervention auction round, they are then again asked to state their minimum selling price. Subsequently, a number is randomly drawn to be the price. If participants’ bid is higher than the price, they keep the backpack. If their bid is equal to or lower than the price, they must sell the backpack at the drawn price.

The experiment is conducted at university campuses in Cologne. The experimenter asks people that pass by the experimenter’s stand if they want to participate in a consumer survey that is conducted by the University of Cologne. They are told that, if they are drawn in a lottery, they can win a backpack or money. If they agree to participate, they are randomly allocated to either the control or the sustainability treatment. Then, participants are given detailed, written instructions that are read aloud to them by the experimenter. To test and enhance participants’ comprehension of the method, one training round with an apple is conducted. Then, participants make their pre-intervention bid. The backpack is available at the experimenter’s stand for participants to inspect. Afterward, depending on the treatment, participants receive one of two different informational sheets about the backpack, either with social sustainability-related information or with ecological sustainability-related information. Then, participants make their post-intervention bid. In the end, participants answer various questions: They are asked if they know the brand (yes/no) and its CSR activities (5 point Likert scale), if they like the design (5 point Likert scale), about their current need of a backpack (5 point Likert scale) and how well they know the backpack market (5 point Likert scale). Then, they are asked to answer demographical questions about gender, age, vocational situation, field of studies, and highest educational degree. Finally, they are asked if they usually buy socially and environmentally sustainable clothes and accessories (2 questions: 5 point Likert scale) and if they have paid more in the past for clothes and accessories that were produced socially and environmentally sustainably (2 questions: 5 point Likert scale). Participants that are allocated to the sustainability treatment are asked additionally if they know Fair Wear Foundation and bluesign (2 questions: yes/no).
Experimental Design Details
Not available
Randomization Method
After subjects agree to participate in the experiment, the experimenter randomly draws a card from an envelope that determines the treatment group.
Randomization Unit
Individual
Was the treatment clustered?
No
Experiment Characteristics
Sample size: planned number of clusters
n.a.
Sample size: planned number of observations
Step 1: 128, Step 2: 308
Sample size (or number of clusters) by treatment arms
Step 1: 64 each, Step 2: 154 each.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
In our previous study (n=368), where no sustainability information included in the control treatment and social & environmental sustainability information were included in the sustainability treatment, we find a mean (standard deviation) of 7.48 (10.48) and 17.31 (17.07), respectively. In this study, we either include only social sustainability or only environmental sustainability information. We take a two-step approach in determining the sample size. First, we assume the effect with only one of the two kinds of sustainability information to be half as strong. Basing the power analysis on this assumption results in a sample size of 128 (64 per treatment) for the current study. Second, we lower our assumed effect size to one-third of the previously found effect, which results in a sample size of 308 (154 per treatment) for the current study.
IRB
INSTITUTIONAL REVIEW BOARDS (IRBs)
IRB Name
IRB Approval Date
IRB Approval Number