Individuals perceptions and responses to transport policies

Last registered on September 11, 2023

Pre-Trial

Trial Information

General Information

Title
Individuals perceptions and responses to transport policies
RCT ID
AEARCTR-0011941
Initial registration date
August 23, 2023

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 24, 2023, 6:46 AM EDT

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

Last updated
September 11, 2023, 2:18 AM EDT

Last updated is the most recent time when changes to the trial's registration were published.

Locations

Region

Primary Investigator

Affiliation
Monash University (Student)

Other Primary Investigator(s)

PI Affiliation
Monash University (Staff)
PI Affiliation
Monash University (Staff)

Additional Trial Information

Status
In development
Start date
2023-09-12
End date
2024-08-24
Secondary IDs
37916 (MUHREC)
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
This paper will explore the effect of narratives and information on individuals' perceptions of electric vehicles (EVs) and policies designed to encourage EV adoption. This paper aims to understand how consumers' EV policy preferences can be influenced by misperceptions about EV technology. An online survey will collect participants' preferences for electric vehicles and incentive schemes that encourage electric vehicle adoption across three treatments; (1) a control treatment, (2) treatment with exposure to EV versus internal-combustion vehicle (ICV) information, (3) treatment with exposure to EV versus ICV narratives. The existing literature explores EV perceptions and the effect of informational interventions; however, there is limited research on how consumers' perceptions of public policy may readjust with information interventions.
External Link(s)

Registration Citation

Citation
Gangadharan, Lata, Siobhan Hutchings and Anke Leroux. 2023. "Individuals perceptions and responses to transport policies." AEA RCT Registry. September 11. https://doi.org/10.1257/rct.11941-1.1
Experimental Details

Interventions

Intervention(s)
The treatments of this survey experiment is exposure to information as a fact sheet or narrative. We will be measuring the effect of information exposure in these different formats on preferences.

The treatment arms will be:
(1) The “Fact Sheet” treatment group provided information about EVs and ICVs designed to correct possible misconceptions.
(2) The “Narrative” treatment group provided the same information but relayed in a narrative format.
(3) The control group which receive no information about EVs. Half of the control group will receive a “History of automobiles” fact sheet designed to occupy the same time as the treatment. The other half will not receives any informative material ("No Information").
Intervention Start Date
2023-09-12
Intervention End Date
2024-08-24

Primary Outcomes

Primary Outcomes (end points)
Preferences for EVs
Preferences for EV policies
Willingness to adjust government budget for EV policies
Primary Outcomes (explanation)
Each of the primary outcomes will be measured by a series of survey questions. The specifics of these questions and how outcomes will be measured are provided in the supporting documentation.

Secondary Outcomes

Secondary Outcomes (end points)
Misperceptions about EVs relative to ICVs
Confidence in the accuracy of perceptions about EVs relative to ICVs
Perception of slow EV adoption as a problem
Perception of the information provided as accurate
Difference in individuals preferences and beliefs about others' preferences
Demographics and personal characteristics
Secondary Outcomes (explanation)
Each of the secondary outcomes will also be measured by a series of survey questions specifics of which are provided in the supporting documentation.

Experimental Design

Experimental Design
This study will measure perceptions and preferences with an online survey experiment. The survey was explicitly created for this experiment by the research team and programmed by PureProfile. The experiment will be a mixed design (combines elements of both a between-subject design and a within-subject design).
Experimental Design Details
In this experiment first, all subjects will be asked questions on demographics and EV preferences. Then participants will be assigned to one of four treatment groups and receive the corresponding intervention. Next, each participant will be asked the same survey questions about EV perceptions, EV preferences, policy preferences and concern for environmental issues. Questions concerning primary outcomes will be asked directly and indirectly to account for the effects of social desirability bias.

Adopting electric vehicles is often perceived as pro-environmental and pro-social behaviour. Respondents on account of social desirability bias may overstate their willingness to adopt, preferences for EV’s and policies. We intend to correct for this bias with indirect questioning. This will involve first asking participants their personal preferences (for example, how likely would you be to purchase an EV). Second, participants will be asked what they believe the most common response was in their state’s capital city or regional areas depending on where the participant lives. Payments of $1 to $2 will be rewarded for correctly guessing the most common response and this will incentivise participants to respond truthfully.

Randomization Method
Participants will be Online workers with PureProfile and will be recruited via PureProfile's website. Assignment to groups will be stratified across gender, location (state and rurality), age and income (annual household) using the least-fill method.
Randomization Unit
Individual
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
No clusters, randomisation will occur at the individual level.
Sample size: planned number of observations
700 respondents and we have a minimum of 233 per treatment arm.
Sample size (or number of clusters) by treatment arms
233 individuals in the “Fact Sheet” treatment group
233 individuals in the “Narrative” treatment group
116 individuals in the “History of automobiles” control group
116 individuals in the "No Information” control group
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Minimum detectable treatment effect is 0.3, with an alpha of 0.05 and 80% power given N=700 and we have a minimum of 233 participants per treatment/control group.
Supporting Documents and Materials

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IRB

Institutional Review Boards (IRBs)

IRB Name
Monash University Human Research Ethics Committee
IRB Approval Date
2023-05-12
IRB Approval Number
37916
Analysis Plan

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Post-Trial

Post Trial Information

Study Withdrawal

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Intervention

Is the intervention completed?
No
Data Collection Complete
Data Publication

Data Publication

Is public data available?
No

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials