Mobility Choices of Employees in a Mobility Budget Scheme – A Randomized Field Experiment

Last registered on November 19, 2021

Pre-Trial

Trial Information

General Information

Title
Mobility Choices of Employees in a Mobility Budget Scheme – A Randomized Field Experiment
RCT ID
AEARCTR-0008470
Initial registration date
November 01, 2021

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
November 05, 2021, 1:49 PM EDT

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

Last updated
November 19, 2021, 12:17 PM EST

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

Locations

Region

Primary Investigator

Affiliation
SRH University Heidelberg

Other Primary Investigator(s)

PI Affiliation
University of Mannheim
PI Affiliation
University of Mannheim

Additional Trial Information

Status
In development
Start date
2021-04-01
End date
2022-03-31
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
Reducing CO2 emissions from the transport sector is an increasingly important policy objective for governments and companies. To allow policymakers to achieve their objectives at a lower political and economic cost, a better understanding of the effectiveness of so called “soft” interventions such as targeted information provision, social norm activation and moral suasion in the transportation domain is needed.

This study will analyze the effects of social comparisons and moral suasion on transport mode choice in a field experiment. We team up with a multinational corporation which provides its German employees with the option to participate in a novel corporate benefit scheme. In this scheme, participants are provided with an individual mobility budget they can use for private transportation expenditures. This mobility budget allows us to observe expenditures for different transport modes over a two-month intervention period and a two-month post-intervention period for approximately 465 participants. In our field experiment, participants will receive e-mails with treatment messages. Treatment group 1 (the control group) will receive a placebo text with information that is not related to transport mode choice. Treatment group 2 will receive a social comparison message contrasting the participants’ individual transportation behavior with the average in a peer group. Treatment group 3 will receive the same social comparison part as in group 2, plus an additional moral suasion part (in the same message). We will use the data from the mobility budget to analyze the effects of these treatments on the use of different transport modes.
External Link(s)

Registration Citation

Citation
Gessner, Johannes, Wolfgang Habla and Ulrich Wagner. 2021. "Mobility Choices of Employees in a Mobility Budget Scheme – A Randomized Field Experiment." AEA RCT Registry. November 19. https://doi.org/10.1257/rct.8470
Experimental Details

Interventions

Intervention(s)
Intervention Start Date
2021-11-02
Intervention End Date
2022-01-02

Primary Outcomes

Primary Outcomes (end points)
Outcomes in the treatment period:
- Individual public transportation expenditures – total per time unit [€/time unit] and changes compared to average pre-treatment time unit [Δ€/ time unit], daily, weekly, monthly, over the treatment period
- Individual public transportation expenditure shares – share during time unit [€ spent on public transportation during time unit/€ spent in the mobility budget during time unit], daily, weekly, monthly, over the treatment period
- Individual public transportation use – count of expenditure items per time unit [Number of expenditure items/time unit], daily, weekly, monthly, over the treatment period
- Individual expenditures for car-related mobility – total per time unit [€/time unit], daily, weekly, monthly, total over the treatment
- Individual expenditure shares for car-related mobility – share during time unit [€ spent on car-related transportation during time unit / € spent in the mobility budget during time unit], daily, weekly, monthly, over the treatment period
- Individual car-related mobility use – count of expenditure items per time unit [Number of expenditure items/time unit], daily, weekly, monthly, over the treatment period
- Analogous outcomes for micro-mobility

Outcomes after the treatment period:
We will analyze all outcomes of the treatment period also for the two-month period following the treatment.
Primary Outcomes (explanation)
- Public transportation expenditures are the sum over expenditures in the spending categories “Local Passenger Traffic Annual Tickets (ÖPNV, e.g. Bus, S-Bahn)”, “Local Passenger Traffic (ÖPNV, e.g. Bus, S-Bahn, RB etc.)”, “Train Local Traffic (IRE, RE, RB, S-Bahn)”, “Train long-distance traffic (IC, ICE, EC, Bahncard 25 & 50)”, “Long-Dist. Traffic: Ways Home-Work (Single or Monthly Tickets)”, "Long-Dist. Traffic: Ways Home-Work (Annual Tickets)", “Long-Distance Coach”
- Car-related mobility expenditures are the sum over expenditures in the spending categories “Taxi (incl. Uber etc.)”, “Hertz Rental Car”, “Car Sharing”, “Shuttle-Pooling”
- Micro-mobility expenditures are the sum over expenditures in the spending categories "e-(Motor)Scooter", "e-Motorscooter", "Bikesharing, -subscriptions and -repairs", “Bike Subscription & Repair Services”

Secondary Outcomes

Secondary Outcomes (end points)
We use the results of a survey which is voluntary among participants and measure the following outcomes for part of the sample:
- Intention to use a transport mode most frequently within the mobility budget. (Answer to the survey question: Which of the following means of transport do you intend to use most frequently with the mobility budget in the next six months under the currently given circumstances?)
- Positive feelings from acting environmentally-friendly. (Answer to the survey question: It makes me feel good to act environmentally friendly. (Agree?))
- Importance of environmental concerns for transportation decisions. (Answer to the survey question: Environmental concerns play no role for my transport mode choice.)
- Importance of behavior observed in the social environment for own decisions (Answer to the survey question: I consider the behavior of my social environment (e.g. Colleagues) when making my own decisions)
- Perceived expectations by the social environment with respect to conformity in transportation decisions (Answer to the survey question: My social environment (e.g. Colleagues) expects me to conform with their transport mode choice)
- Perceived expectations by the social environment with respect to environmentally-friendly behavior. (Answer to the survey question: My social environment (e.g. Colleagues) expects me to act environmentally friendly)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
The sample contains all participants in a pilot for mobility budgets at our partner company. The participants are employees at a multinational company working at the companies’ German business locations. They selected into participation in the pilot. In the pilot, participants receive a budget that they can use for private mobility expenses using different modes of transportation. We observe the participants’ expenditures for different transport modes on a daily resolution. Starting in November 2021, we will try to alter participants’ expenditures for public transport (and thus all other categories, as well), by sending emails on a fixed day of the week every other week over a treatment period of two months. Expenses made by household members of the participants will not be considered.
There are 3 treatment arms: treatment 1 serves as a control and receives only a placebo message without information related to transport mode choice. Treatment 2 is intended to activate a social norm with a social comparison message. Treatment 3 combines a moral appeal related to climate change with the social norm message in Treatment 2. We observe transportation expenditures for the 7 months prior to the treatment period and for 3 months after the treatment period.
Experimental Design Details
Randomization Method
Stratified randomization: We will split the sample into strata based on previous transportation expenditures observed in the mobility budget scheme and on the business locations the participants work at. Within the strata, we will randomly assign 1/3 of the participants into each treatment arm. Randomization is done in R.
Randomization Unit
Employee participating in the corporate benefit scheme
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
No clustering
Sample size: planned number of observations
Approximately 465 employees.
Sample size (or number of clusters) by treatment arms
The sample is split with equal probability into the three treatment arms. Each arm will contain roughly 1/3 * 465 participants = roughly 155 participants per treatment arm.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB

Institutional Review Boards (IRBs)

IRB Name
Ethics Committee at the University of Mannheim
IRB Approval Date
2021-11-18
IRB Approval Number
EK Mannheim 58/2021

Post-Trial

Post Trial Information

Study Withdrawal

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

Request Information

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