Nudge for Sanitation: Experimental Evidence from China

Last registered on June 28, 2023
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Pre-Trial

Trial Information

General Information

Title
Nudge for Sanitation: Experimental Evidence from China
RCT ID
AEARCTR-0011596
Initial registration date
June 27, 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
June 28, 2023, 5:10 PM EDT

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

Locations

Country
China
Region
Chongqing

Primary Investigator

Name
Yanlin Wan
Affiliation
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Other Primary Investigator(s)

PI Name
Xu Zhang
PI Affiliation
HKUST(Guangzhou)
Contact Investigator

Additional Trial Information

Status
On going
Start date
2022-07-01
End date
2023-08-31
Keywords
Behavior, Environment & Energy
Additional Keywords
RCT, Rural Toilet Revolution, Sanitation, Sustainable Development
JEL code(s)
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
This study investigates the impact of informational nudges on villagers' participation decisions in China's Rural Toilet Revolution (RTR). A randomized controlled trial was conducted in a southwestern region of China, where six RTR advocacy videos were designed as informational nudges based on local residents' information demand for RTR programs. The videos respectively highlight the benefits of RTR participation, the harms of poor sanitation, and techniques for toilet upgrades, with and without a former RTR participant calling for engagement. This study finds that explaining the required techniques of RTR participation was the most effective in motivating local villagers' willingness to engage in RTR while making the health benefits of RTR participation salient is the most significant factor in incentivizing their uptake of RTR programs in the long run. The results indicate the importance of technical attributes and benefits associated with RTR for the target audience and underline information barrier removal and peer messenger presence as useful nudges to promote public campaigns like RTR.
External Link(s)

Registration Citation

Citation
Wan, Yanlin and Xu Zhang. 2023. "Nudge for Sanitation: Experimental Evidence from China." AEA RCT Registry. June 28. https://doi.org/10.1257/rct.11596-1.0
Sponsors & Partners
Experimental Details

Interventions

Intervention(s)
The main intervention of the field experiment is to invite rural residents to watch a video clip that lasts around 6 minutes and there are a total number of six different treatment videos. Based upon the concept of information salience and messenger effect, we adopt a 3 × 2 factorial design where the information salience factor of the experiment video refers to the salience and visibility of three different aspects of RTR programs (benefits of RTR participation, harms of poor sanitation, and techniques for toilet upgrade), while another factor messenger effect indicates whether or not there is the presence of a peer villager who participated in RTR calling for engagement.

Intervention Start Date
2022-07-01
Intervention End Date
2022-09-30

Primary Outcomes

Primary Outcomes (end points)
1. Level of willingness to participate measured through a Likert scale (0 to 10); 2. Enrollment status in a new RTR project.
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
1. Level of reliance on government to address private sanitation issues; 2. Level of RTR understanding
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
The main intervention of the field experiment is to invite rural residents to watch a video clip that lasts around 6 minutes and there are a total number of six different treatment videos. Based upon the concept of information salience and messenger effect, we adopt a 3 × 2 factorial design where the information salience factor of the experiment video refers to the salience and visibility of three different aspects of RTR programs (benefits of RTR participation, harms of poor sanitation, and techniques for toilet upgrade), while another factor messenger effect indicates whether or not there is the presence of a peer villager who participated in RTR calling for engagement. The experimental videos are all about the advocacy of RTR and each of the treatment videos incorporates six parts: RTR background, one call-for-participation message, technical attributes of RTR participation, benefits of RTR, harms of poor sanitation, and ending remarks that pinpoint the village committee as a reliable information source. The realization of salient information about different TR aspects is through highlighting the particular aspect with a longer and more explicit explanation but the total video duration remains the same. For example, to draw the attention of experimental subjects to technical attributes, the video spends around 2 minutes elaborating on how to construct and maintain sanitary toilets and the three-chamber harmless septic, while introducing the remaining parts in around 4 minutes in total whereas the other two aspects of TR (benefits and harms) takes around 30s - 50s each.

Experimental Design Details
The unit of randomization is village in order to minimize potential biases due to communication contamination while the unit of analysis is the experimental subject that receives the treatment in each arm. We finally recruited 10-15 subjects in each treated village and in the control village (985 participants in the end), which can provide sufficient statistical power for the experiment. In each experiment arm, participation in the experiment is entirely voluntary. Villagers shall not come from the same household and this will be further checked after their registration in the experiment by asking or by administrative records. Self-selection into the experiment could be a concern of the external validity of the experiment, and this is one of the limits of this study, while its effects will be canceled out by cross-group comparison so that internal validity can be guaranteed by testing baseline differences between different treatment arms.
Randomization Method
Randomization was done in the office by stata
Randomization Unit
Village
Was the treatment clustered?
Yes

Experiment Characteristics

Sample size: planned number of clusters
93 villages
Sample size: planned number of observations
Number of units: 985 villagers Number of observations: 1,970
Sample size (or number of clusters) by treatment arms
21 villages control

72 villages treatment
T1(highlighting techniques required + messenger presence): 12 villages
T2(highlighting techniques required + no messenger presence) : 12 villages
T3(highlighting benefits of participation + messenger presence): 12 villages
T4(highlighting harms of no participation + messenger presence): 12 villages
T5(highlighting benefits of participation + no messenger presence): 12 villages
T6(highlighting harms of no participation + messenger presence): 12 villages

Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Supporting Documents and Materials

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IRB

Institutional Review Boards (IRBs)

IRB Name
The Hong Kong University of Science & Technology Human Research Ethics Protocol
IRB Approval Date
2022-08-14
IRB Approval Number
HREP-2022-0142
Analysis Plan

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