|
Field
Trial End Date
|
Before
May 01, 2020
|
After
July 01, 2020
|
|
Field
Last Published
|
Before
April 21, 2020 04:41 AM
|
After
May 12, 2020 03:55 AM
|
|
Field
Intervention Start Date
|
Before
January 17, 2019
|
After
May 13, 2020
|
|
Field
Intervention End Date
|
Before
May 01, 2020
|
After
May 27, 2020
|
|
Field
Randomization Method
|
Before
Observational Study:
All master students of the University of Kassel as well as bachelor students from two to three Chilean universities (yet to be determined) have the possibility to take part in the survey.
Intervention (natural field experiment as a randomized trial with non-compliance)
Participants of the survey are randomly assigned to one out of two treatment groups in equal shares. Treatment group one has the possibility to play the game. The second group gets specially designed newsletter that gives them information on the climate-relevance of food choices.
Spillover-Experiment (Framed field experiment as a randomized trial)
Using a factorial-design, participants of the survey are randomly assigned to one out of two groups. The first group have to decide how much of 50 €, which they can win with a probability of 1:20, they want to give to an environmental origination (Deutsche Umweltstiftung) and afterwards which amount of another 50 € the can win with the same probability they want to donate to a social organization (Welthungerhilfe). The second treatment group firstly decides about how much to give to the social organization and afterwards to the environmental organization.
|
After
Observational Study:
All master students of the University of Kassel as well as bachelor students from two Chilean universities have the possibility to take part in the survey.
Intervention (natural field experiment as a randomized trial with non-compliance)
Participants of the survey are randomly assigned to one out of two treatment groups in equal shares done in office by a computer. Treatment group one has the possibility to play the game. The second group is provided with a digital food diary. The control group receives a non-food related survey task.
Spillover-Experiment (Framed field experiment as a randomized trial)
Using a factorial-design, participants of the survey are randomly assigned to one out of two groups. The first group has to decide how much of their real-money endowment, which they can win with a probability of 1:20, they want to give to an environmental origination. In a second giving experiment afterward, they have again to decide on how much of another endowment, win with the same probability, they want to donate to a social organization. Which organization is named first is randomized.
|
|
Field
Randomization Unit
|
Before
Individual (students)
|
After
friendship groups of students
|
|
Field
Was the treatment clustered?
|
Before
No
|
After
Yes
|
|
Field
Planned Number of Clusters
|
Before
two clusters (University of Kassel, Chilenean University)
|
After
one University in Chile
2 treatment groups: game, diary + one control group
each treatment group is divided by friendship: We, therefore, obtain in each treatment group a friendship group and a non-friendship group
|
|
Field
Planned Number of Observations
|
Before
The population of inference for the survey consists in the master students of the university of Kassel and of the bachelor students of two or three Chilean Universities (participating universities are still to be determined). The students are offered an online and paper-and-pencil questionnaire via a mailing list of the university and within their respective major courses. We expect a quota of approx. 850 questionnaires in the first wave of the first location (Germany) and 1000 to 2500 questionnaires in the first wave of second location (Chile) (see power calculations for detail).
|
After
The population of inference for the survey consists of the master students of the University of Kassel and of the bachelor students of one Chilean University. The students are offered an online and paper-and-pencil questionnaire via a mailing list of the university and within their respective major courses. We expect a quota of approx. 850 questionnaires in the first wave of the first location (Germany) and 1000 to 2500 questionnaires in the first wave of the second location (Chile) (see power calculations for detail).
|
|
Field
Sample size (or number of clusters) by treatment arms
|
Before
for University of Kassel: approx 750 game intervention, 750 newsletter
for Chile pprox. 1200 game and 1200 newsletter
|
After
for Chile
200 friendship group game
200 friendship group diary
200 non-friendship group game
200 non-friendship group diary
200 control group
|
|
Field
Power calculation: Minimum Detectable Effect Size for Main Outcomes
|
Before
see PAP
|
After
Our basic premise is that we are testing the hypothesis under an α<=5% and are trying to achieve a statistical power >=80%. Based on the simulation study, the final total sample size should be at least in the range of N=2000 to N=3000.
Update: By reducing the non-compliance through monetary incentives and by adjusting our randomization procedure to the friendship group level we now assume that we are able to achieve a statistical power of about 80% with a sample size of N=1000
|
|
Field
Public locations
|
Before
No
|
After
Yes
|