The Functioning of Self-Governing Sharing Economies.

Last registered on May 31, 2021

Pre-Trial

Trial Information

General Information

Title
The Functioning of Self-Governing Sharing Economies.
RCT ID
AEARCTR-0004088
Initial registration date
June 21, 2019
Last updated
May 31, 2021, 11:53 AM EDT

Locations

Primary Investigator

Affiliation
University of Groningen

Other Primary Investigator(s)

PI Affiliation
University of Groningen

Additional Trial Information

Status
On going
Start date
2019-05-06
End date
2021-09-01
Secondary IDs
Abstract
New forms of market mechanisms in which participants share products are becoming increasingly popular. In this project, we address the question whether not-for-profit initiatives in sharing economies, where at most informal rules are at play, can sustain in the long-run and to what extent free-riding occurs. The experimental intervention, which we preregister, is part of a larger study in which we collect field data. For the experimental part, a sample of local markets is randomized into a treatment and control group. After baseline field data have been collected, members of the treatment group receive a positive supply shock and we test whether this shock has a transitory or more permanent effect.
External Link(s)

Registration Citation

Citation
Schippers, Anouk and Adriaan Soetevent. 2021. "The Functioning of Self-Governing Sharing Economies.." AEA RCT Registry. May 31. https://doi.org/10.1257/rct.4088-1.7000000000000002
Former Citation
Schippers, Anouk, Anouk Schippers and Adriaan Soetevent. 2021. "The Functioning of Self-Governing Sharing Economies.." AEA RCT Registry. May 31. https://www.socialscienceregistry.org/trials/4088/history/92826
Experimental Details

Interventions

Intervention(s)
This study collects field data on an unregulated sharing economy to observe the extent to which these markets function without regulation. In the field experimental part, which we preregister, a sample of local markets is randomized into a treatment and control group. After baseline data have been collected, members of the treatment group receive a positive supply shock and we test whether this shock has a transitory or more permanent effect.
Intervention Start Date
2019-06-10
Intervention End Date
2019-09-15

Primary Outcomes

Primary Outcomes (end points)
The primary outcome variable of our field experimental intervention is the turnover rate of our experimental units compared to the control units.





Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
The secondary outcome variable of our field experimental intervention is the multiplier effect that our experimental units have on new non-experimental units in the treatment group compared to new control units.
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
For the field experimental part of this study, we randomize a number of local markets into a treatment and control group. After baseline data have been collected, members of the treatment group immediately receive a positive supply shock while members of the control group receive this shock later in the study (a few weeks before the end).
Experimental Design Details
The study started in May and lasts for almost six months. Each owner submits on a weekly basis the stock of books in their library and indicates of each book whether it was added or taken out by themselves or by a passenger.

The study starts in May 2019. During the first five weeks of the study, no treatment variation takes place. This covers the baseline period in which owners weekly register the stock of books in their library. After this period, in June 2019, the treatment variation is implemented. Hence, the months June, July and August 2019 are our experimental period. The libraries in the control group will receive the treatment in August or September 2019. 30 libraries are allocated to the treatment group and 28 libraries to the control group.

The treatment consists of a package of books that each owner receives to be placed in their library. The package of books is exactly the same for the treatment and the control group, only the timing of delivery differed. Owners in the treatment group received the package of books one month after the start of the study, while owners in the control group will receive the package of books in August or September 2019. The value of the package is set at 50 euro (around 47 euro second-hand price, around 15 per book) such that it was higher than the average second-hand book price as reported in the first week of the study (which was around 9.50 euro).

Owners of libraries in the treatment group (nor in control group) are not informed about the experimental variation in book arrivals. Owners of libraries in the control group are informed about the timing of their delivery. All owners of the libraries (control and treatment group) continued the study in the experimental phase as before, so they submitted on a weekly basis the stock of books.

In april-august 2020, a survey was sent out to the library owners and flyers were placed in the libraries to invite library users to complete the survey. The survey contained questions about why owners started their library, and why users visited the library and how often. Additionally, both versions of the survey contained a social norms measure (Krupka and Weber) and a standard public goods game. The social norms measure consisted of 7 items that which owners and users evalueted on a 1 (= very socially inappropriate) to 4 (= very socially appropriate) scale. The PGG consisted of investing 10 euros in the common project (all contributions*1.6 and divided over 4 participants) or keep it for themselves.
Randomization Method
30 local markets were allocated to the treatment group and 28 to the control. Randomization was stratified based on four-digit postal codes of the local market and the number of observations per local market as reported in the first week of the study. Randomization was done in the office by a computer using Stata-code.
Randomization Unit
Local market.
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
58 local markets.
Sample size: planned number of observations
58 local markets, per local market a time series of 24 observations will be collected.
Sample size (or number of clusters) by treatment arms
28 local markets in the control group, 30 local markets in the treatment group
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Supporting Documents and Materials

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

Request Information
IRB

Institutional Review Boards (IRBs)

IRB Name
Institutional Review Board of the Faculty of Economics and Business, University of Groningen
IRB Approval Date
2019-06-08
IRB Approval Number
20190322-7870

Post-Trial

Post Trial Information

Study Withdrawal

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

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