Simplifying police bail notices to increase court attendance

Last registered on January 14, 2021
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Pre-Trial

Trial Information

General Information

Title
Simplifying police bail notices to increase court attendance
RCT ID
AEARCTR-0007018
Initial registration date
January 13, 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
January 14, 2021, 11:56 AM EST

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

Locations

Country
New Zealand
Region

Primary Investigator

Name
Nathan Chappell
Affiliation
The Behavioural Insights Team
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Other Primary Investigator(s)

PI Name
Sarah Hayward
PI Affiliation
The Behavioural Insights Team
Contact Investigator
PI Name
Lance Tebbutt
PI Affiliation
New Zealand Police
Contact Investigator
PI Name
Alex Gyani
PI Affiliation
The Behavioural Insights Team
Contact Investigator

Additional Trial Information

Status
Completed
Start date
2020-06-02
End date
2020-11-30
Keywords
Crime, Violence, & Conflict
Additional Keywords
JEL code(s)
Secondary IDs
Abstract
In 2018, the New Zealand government promised to reduce the prison population by 30% within the next 15 years. This goal arose because of recent increases in the number of prisoners, and because New Zealand has one of the highest incarceration rates in the OECD. One way to reduce the prison population and increase the efficiency of the justice system is to increase the number of people who appear in court when released on Police bail.

In this trial, the Behavioural Insights Team has partnered with New Zealand Police to test whether a behaviourally-informed new police bail notice can increase court attendance by defendants. The new notice draws on concepts from behavioural science to encourage behaviour change, including simplification, reciprocity and social norms.
External Link(s)

Registration Citation

Citation
Chappell, Nathan et al. 2021. "Simplifying police bail notices to increase court attendance ." AEA RCT Registry. January 14. https://doi.org/10.1257/rct.7018-1.0
Sponsors & Partners

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Experimental Details

Interventions

Intervention(s)
The intervention draws on elements of the re-design of apprehended domestic violence orders (ADVOs) by BIT in Australia, and by the re-design of court appearance notices for minor misdemeanors by ideas42 in New York. The most important elements of the intervention are:

1) Simplification: The new notice puts the most important information at the top of the document, uses simpler and more direct language, and includes the address of the court in addition to relevant phone numbers and URLs to make it easy for defendants to get more information.

2) Social norms: The new notice uses social norms by telling defendants that most people like them appear in court when necessary. Social norms have been proven effective in a number of domains, including a recent trial in New Zealand getting people to pay their fines on time.
Intervention Start Date
2020-06-02
Intervention End Date
2020-11-30

Primary Outcomes

Primary Outcomes (end points)
Whether a defendant appears in court at the required date and time after release on police bail
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
The trial takes the form of a 2-armed, clustered randomised controlled trial with randomisation at the custody officer level and stratification by custody team, using six police stations as trial partners.
Experimental Design Details
Randomization Method
Randomisation in this trial is done using the 'stratified' function within the 'splitstackshape' package in R, to randomise custody officers into the treatment or control arm within each stratum (with custody teams being the strata).
Randomization Unit
Randomisation is clustered at the custody officer level.
Was the treatment clustered?
Yes

Experiment Characteristics

Sample size: planned number of clusters
131 custody officers
Sample size: planned number of observations
1000 defendants
Sample size (or number of clusters) by treatment arms
66 treatment custody officers, 65 control custody officers
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Supporting Documents and Materials
IRB

Institutional Review Boards (IRBs)

IRB Name
IRB Approval Date
IRB Approval Number
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