Promoting pro-environmental behavior of tourists using pro-environmental messaging: an experimental study in Vietnam

Last registered on December 23, 2024

Pre-Trial

Trial Information

General Information

Title
Promoting pro-environmental behavior of tourists using pro-environmental messaging: an experimental study in Vietnam
RCT ID
AEARCTR-0015030
Initial registration date
December 22, 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
December 23, 2024, 1:48 PM EST

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

Locations

Region

Primary Investigator

Affiliation
Beijing Normal University

Other Primary Investigator(s)

PI Affiliation
PI Affiliation

Additional Trial Information

Status
On going
Start date
2024-11-22
End date
2024-12-27
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
In an experiment that combines survey and field observations, we examine the effectiveness of different framings of the pro-environmental messages in the promoting pro-environmental behavioral changes in the highly hedonic context of tourism. We experimentally manipulate the assignment of two framings, i.e., a normative framing and a hedonic framing, in a survey targeting tourists on ferry trips in Vietnam. We set to examine with framing is more effective in changing actual behavior of tourist with actual behavioral measures from the field and the heterogeneity in the treatment effects with regard to hedonic motives held by the tourists.
External Link(s)

Registration Citation

Citation
Ho , Thong, Zihan Nie and Chau Tran. 2024. "Promoting pro-environmental behavior of tourists using pro-environmental messaging: an experimental study in Vietnam." AEA RCT Registry. December 23. https://doi.org/10.1257/rct.15030-1.0
Sponsors & Partners

Sponsors

Experimental Details

Interventions

Intervention(s)
Pro-environmental messaging aiming at promoting pro-environmental behavior among tourists. with two different framing of the message: normative framing and hedonic framing.
The hedonic framing of the pro-environmental message (Hedonic) refers to making the message stress how acting pro-environmentally can help increase the psychological pleasure of the vacation.
The normative framing of the pro-environmental message (Normative) appeals to individuals’ pro-environmental preference and personal and social norms, which is typical in pro-environmental messaging in every day context.
The intervention is delivered in the middle of a tourist survey conducted on a popular tourism route.
Intervention (Hidden)
This intervention takes form of a pro-environmental message shown to tourists on a ferry trip to a famous tourist destination in southern Vietnam. The intervention is delivered in the middle of a tourist survey.
In the intervention, respondents read a pro-environmental message that has two parts. Ih the first part, respondents see a picture of the tourists on the ferry with a general message about the environmental issues faced by tourism in Vietnam that reads “Vietnam’s natural beauty has attracted tourists from all over the world to come and enjoy themselves. However, with the increasing number of tourists and the development of tourism, the natural environment is under increasing pressure and environmental pollution starts to erode the beautiful sceneries.” This message is the same for all respondents.
In the second part, the respondent read a paragraph of pro-environmental messages that is delivered in as a call for changes from the tourists.
We experimentally manipulate the framing of this message in the second part. The message is delivered in two different framings, one with hedonic framing and one with normative framing.
The hedonic framing of the pro-environmental message (Hedonic) refers to making the message stress how acting pro-environmentally can help increase the psychological pleasure of the vacation. The message reads as follows: “Fellow tourists, let’s keep Vietnam beautiful. Simple actions like reducing single-use plastics and dispose of trash properly could make our trip more memorable. A CLEAN ENVIRONMENT MEANS A BETTER VACATION—LET’S MAKE EVERY MOMENT MORE ENJOYABLE!”
The normative framing of the pro-environmental message (Normative) appeals to individuals’ pro-environmental preference and personal and social norms, which is typical in pro-environmental messaging in every day context. The message reads as follows: “As responsible travelers, it’s our duty to protect Vietnam’s beauty. Simple actions like reducing plastic use and properly disposing of waste help preserve the environment for future generations. Act now to keep Vietnam clean—our choices today matter. IT IS OUR RESPONSIBILITY TO MAINTAIN A CLEAN ENVIRONMENT.”
The intervention is delivered in the middle of a tourist survey conducted on a popular tourism route, i.e. a ferry trip from Ho Chi Minh City to Vũng Tàu.
Intervention Start Date
2024-11-22
Intervention End Date
2024-12-27

Primary Outcomes

Primary Outcomes (end points)
The primary outcome variable is the consumption of single-use items. We frame and observe the consumption decisions in a natural gift redeem setting. We offer the respondents a fruit tea and a cake at the terminal café the compensation for participation. The respondents are asked to order from a menu in advance to save waiting time upon arrival. An order includes what type of fruit tea and cake they want and what accessory items they want to have alone with the tea and cake. The accessory items include typical single-use items such as straws, spoon, stirring sticks, cup holders and plastic bags.
We count the total number of items used as the main outcome variable in the analysis.
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Behavioral intentions measured with survey questions. Intentions are measured on a 1-7 Likert scale.
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
We conduct a survey experiment among tourists in a natural tourism setting to study the research questions. Tourists are invited to join a survey about their views on the topics related to their visits by the enumerators. The survey contains largely three sections. In first section, we elicit respondent’s attitudes and perceptions with regard to hedonic motivations and environmental concerns, as well as individual characteristics and trip information. In the second section, we introduce the pro-environmental messaging that calls for pro-environmental behavioral changes during their trips. We randomly assign respondents to one of the two version of pro-environmental messaging, one with hedonic framing and one with normative framing. In the third section of the survey, we elicit respondents’ pro-environmental behavioral intentions and policy support as self-reported outcome variable.
The pre-intervention questions are to obtain basic information on the respondent and understand their “natural” attitudes and perceptions towards vacations and environmental issues, with a focus on hedonic goals and motivations. This section provides baseline information that will be used to explore effect mechanisms and heterogenous effects.
The intervention occurs as a message in the middle of the service. The intervention design had already been described above. Beside the two treatment conditions, we have a control group where respondents only see the pictures in the interim between the first and third survey sections.
We use the between-subject design, where one respondent will only experience one treatment arm.
Because tourists tend to travel in groups, to reduce contamination across treatment arms, we randomize the treatment assignment at group level.
After delivering the intervention, we elicit respondents’ pro-environmental behavioral intentions with survey questions and observe their pro-environmental behavior in a field setting. The observed pro-environmental behavior is our primary outcome variable and the pro-environmental behavioral intentions are the secondary outcome variables.
Experimental Design Details
We conduct a survey experiment among tourists in a natural tourism setting to study the research questions. Tourists are invited to join a survey about their views on the topics related to their visits by the enumerators. The survey contains largely three sections. In first section, we elicit respondent’s attitudes and perceptions with regard to hedonic motivations and environmental concerns, as well as individual characteristics and trip information. In the second section, we introduce the pro-environmental messaging that calls for pro-environmental behavioral changes during their trips. We randomly assign respondents to one of the two version of pro-environmental messaging, one with hedonic framing and one with normative framing. In the third section of the survey, we elicit respondents’ pro-environmental behavioral intentions and policy support as self-reported outcome variable.
1. Pre- intervention attitudes and perceptions
The pre-intervention questions are to obtain basic information on the respondent and understand their “natural” attitudes and perceptions towards vacations and environmental issues, with a focus on hedonic goals and motivations. This section provides baseline information that will be used to explore effect mechanisms and heterogenous effects.
Specifically, we elicit respondents’ hedonic motives using a set of questions. We also elicit respondents’ hedonic goals using a question where respondents are asked state their goals of the trip.
We also include questions on awareness of environmental issues, perceived outcome efficacy, ascribed responsibility and personal norm to understand and control for individual heterogeneity.
Because literature has evidence that people often act differently in hedonic context such as vacation from in everyday life, we also ask respondents about their pro-environmental behavioral at home with a set of behavioral frequency questions.
To avoid demand effect stemmed from being overly focused on environmental issues in the questions, we also included the “decoy” questions on other issues.
2. Interventions: pro-environmental messaging
The intervention occurs as a message in the middle of the service. The intervention design had already been described above. Beside the two treatment conditions, we have a control group where respondents only see the pictures in the interim between the first and third survey sections.
We use the between-subject design, where one respondent will only experience one treatment arm.
Because tourists tend to travel in groups, to reduce contamination across treatment arms, we randomize the treatment assignment at group level.
3. Post-intervention stage: outcome variables
The primary outcome variable in our study is the tourist’s actual pro-environmental behavior. Because the pro-environmental messaging aims to encourage tourists to engage in general pro-environmental behavior later during their visits, ideally, we would like observe tourists’ pro-environmental after arrival as they go on to visit various places. However, due to the difficulty in tracing tourists after they get off the ferry, in this study, we measure tourists’ pro-environmental behavior using their decisions on what to consume upon the arrival of the ferry, when they are still on-board.
Specifically, we present the consumption decisions to the respondents as compensations for participation in the survey. We offer the respondents a gift card that can be redeemed for a refreshing drink at the terminal café at Vung Tau. We ask the respondents to order their drinks in advance, so that the drinks can be prepared in advance and save waiting time upon arrival. Each respondent can choose one fruit tea and up to two cakes from the menu, as well as a bag of chips. There are four options for fruit tea and four options for cakes. More important, on the menu, there are additional options to choosing accessory items, such as straws, teaspoons, cake spoons, cup holders, plastics bags and tissue papers. These accessory options are framed as a way to facilitate the preparation of the drinks and speed up the process. The menu is printed on the back of the gift card. Respondents place their order by checking the correspondent boxes on the menu for tea and cakes and fill in the number of each accessory items they want to have, with the default (not filling in anything) to be zero.
We use the choices of these items as the measure for pro-environmental behavior. Given the relatively weak waste management system in Vietnam, and that most of these items are made of plastics, using more accessory items typically implies larger environmental impacts. In this way, we can obtain a measure of actual behavior with environmental consequences in a natural tourism setting. This is the main outcome variable in this study.
Each gift card consists of two sections: the main body for passengers to select their options and a stub on the side for enumerators to record these choices. Each gift card includes three pieces of information to link it to the survey: the survey date (determined by the gift card’s expiration date), the seat number, and the gift card ID. Because the consumption behavior is measured separately from the survey.
Beside the pro-environmental behavior measure described above, in the survey, we also elicit tourists’ behavioral intentions, which are widely used as outcome variables in the literature. We ask the respondents about how likely they are going to adopt a set of common behavior with environmental consequences, on a 7-point Likert scale. The pro-environmental behavior including reducing waste, picking up litter, avoiding using plastic bags, which are closely related to our behavioral outcome measures.
To mitigate demand effect stemming from being too focused on pro-environmental behavior in the questionnaire, we also include a few behaviors in other domains including donating to protection the parks, donating to preservation of historical and cultural buildings, purchasing traditional handicrafts to support local artisans and supporting organizations advocating for a ban on animal abuse in tourism.
Beside the outcome variables, we also elicit respondents’ subjective valuation of the pro-environmental messaging and their view of the survey to validify the manipulation.
4. Hypothesis
Pro-environmental messaging can improve tourists’ pro-environmental behavior intention and actual pro-environmental behavior. (Control vs. Hedonic & Normative)
Hedonic framing of pro-environmental messaging is more effective than normative framing in the context of tourism. (Hedonic vs. Normative)
Hedonic framing is more effective for respondents with stronger hedonic motives. (Control vs. Hedonic, interaction with hedonic motives)
Normative framing is less effective for respondents with stronger hedonic motives. (Control vs. Normative, interaction with hedonic motives)
Potential attitude-behavior gap: positive effects on behavioral intentions, but no effect on behavior. If the gap exists, we expect heterogeneity in the gap. Those who hold strong hedonic motives will shower larger gap. Perhaps similar effects on intention, much small effect on behavior.

5. Data collection
We carried out the study during Nov. - Dec. 2024. Our sampling frame is all the passengers travelling on the Greenline DP’s ferry trips from HCMC to VT. We choose passengers on the one-way trip because visitors, particularly foreigner visitors, usually arrive in HCMC first and travel from HCMC to visit different sites in the neighboring regions. Our polit suggests that passengers on the return trip from VT to HCMC are often tired and more difficult to approach. We also want to conduct the study before their visits so that the interventions are more likely to induce actual behavioral changes during their visits.
The ferry has a variable schedule based on the expected flow of passengers. On average, an enumerate can travel with the ferry for two round trips between HCMC and VT per day during our studied period. During each trip, the enumerator invites all passengers one-by-one on the ferry to participate in our study. The passengers are also informed of the study with a leaflet placed in the seat pocket. In case of group travelers, the enumerator will first confirm group members on the spot, and then invite all adult group members. To randomize at group level, the enumerator would generate a group ID on the spot with a roll of dice. The random allocation of treatment arms is based on the group IDs. All respondents from the same group are asked to fill in the group ID to start survey.
The enumerator would make it clear to the passengers that the survey is part of an academic project and reassure the passengers that the survey will not collect any information other than their answers in the survey and they are free to not answer certain questions.
In case that passengers refuse to participate, the enumerators would try to record the seat numbers and some observable individual characteristics (gender, domestic/foreign, group/alone) to evaluate the potential non-response bias.
Randomization Method
Randomization by rolling a dice on site.
Randomization Unit
Randomization by tourist groups. The enumerator on site would identify respondents traveling in the same group and assign the respondents from a group to the same treatment arm.
Was the treatment clustered?
Yes

Experiment Characteristics

Sample size: planned number of clusters
About 375 tourist groups (assuming the average group size is 4)
Sample size: planned number of observations
1,500 tourists from around 375 groups
Sample size (or number of clusters) by treatment arms
00 from about 125 groups in each treatment arm.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Assuming intra-cluster correlation of 0.5, with a power of 0.8 and significant level of 0.05, we can obtain a minimum detectable effect size of 0.28 SD.
IRB

Institutional Review Boards (IRBs)

IRB Name
The EEPSEA (Economy and Environment Partnership for Southeast Asia) Research Ethics Committee
IRB Approval Date
2024-11-22
IRB Approval Number
E01-11-2024

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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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