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Increasing workplace giving
Last registered on April 02, 2018


Trial Information
General Information
Increasing workplace giving
Initial registration date
March 20, 2018
Last updated
April 02, 2018 10:40 PM EDT
Primary Investigator
Behavioural Economics Team of the Australian Government
Other Primary Investigator(s)
PI Affiliation
Behavioural Economics Team of the Australian Government
Additional Trial Information
In development
Start date
End date
Secondary IDs
This pilot study will examine the effectiveness of various behaviourally informed approaches in increasing workplace giving (WG).
External Link(s)
Registration Citation
Greenwell, Harry and Shea Houlihan. 2018. "Increasing workplace giving ." AEA RCT Registry. April 02. https://doi.org/10.1257/rct.2790-2.0.
Former Citation
Greenwell, Harry, Shea Houlihan and Shea Houlihan. 2018. "Increasing workplace giving ." AEA RCT Registry. April 02. http://www.socialscienceregistry.org/trials/2790/history/27590.
Experimental Details
Two different behaviourally informed interventions will be distributed to employees.
Intervention Start Date
Intervention End Date
Primary Outcomes
Primary Outcomes (end points)
WG participation (joining or not joining), and change in average fortnightly WG donation
Primary Outcomes (explanation)
Secondary Outcomes
Secondary Outcomes (end points)
Total amount of money directed to workplace giving each fortnight; change in comprehension of workplace giving; charities receiving donations; number of email read receipts; and number of click-throughs from email to WG sign-up page
Secondary Outcomes (explanation)
Experimental Design
Experimental Design
An unbalanced three-arm RCT randomized at the individual level and a pre-post observational trial. Data will be data collected at two follow-up periods: two and four weeks after intervention delivery.
Experimental Design Details
First, the RCT involves testing the effectiveness of one treatment condition against two control conditions. The treatment and attention control emails will be delivered on a themed day to connect with the agency’s organisational culture. The treatment condition is an email informed by BI, including warm glow, pure altruism, social norms. The BI email will come from a lead messenger and will provide a link where staff can sign up to workplace giving. The attention-control condition incorporates a simple reminder email informing participants that the department facilitates WG. Finally, the pure control condition incorporates the current business-as-usual approach. Employees are allowed to opt in to WG upon taking up work in the department or at any subsequent time, but receive no reminder or encouragement to do so. Individual staff in multiple government agency offices will be randomly assigned to the treatment, attention-control, or pure control condition. The assignment ratio will be 2:2:1 (40% treatment, 40% attention-control, and 20% pure control). We think this unbalanced design is justified because we do not anticipate the same level of variance in pure control as in the treatment or attention control. To wit, we do not expect to detect any effect in either of the two primary outcome measures in the pure control arm. We therefore feel it is reasonable to reduce the pure control sample size in favour of increasing the power of the treatment and attention control groups. Second, the pre-post observational trial tests the effectiveness of a small gift to increase workplace giving by inducing feelings of reciprocity, and the BI email, in one central office. The gift is constituted of an international recipe card and metal fork to strengthen the link to the civic holiday and generate a social response. The recipe cards are intended to facilitate group discussion to help promote a culture of WG, and the fork is a durable gift to increase feelings of reciprocity. Gifts will be distributed to the desks of all staff in the central office (687 employees) before office hours on 21 March 2018, with a note asking recipients to consider workplace giving.
Randomization Method
Trial 1 (RCT): Unbalanced (2:2:1 ratio) randomisation incorporating stratification on one binary variable will occur at the individual level using standard STATA algorithm.

Trial 2 (pre-post): Non randomised.
Randomization Unit
Trial 1 (RCT): Unbalanced, stratified randomisation will occur at the individual level.

Trial 2 (pre-post observational trial): Non-randomised, but the unit of analysis remains at the individual level.
Was the treatment clustered?
Experiment Characteristics
Sample size: planned number of clusters
Not applicable.
Sample size: planned number of observations
2,002 observations measured at baseline and two follow-up points (two and four weeks after intervention delivery)
Sample size (or number of clusters) by treatment arms
Participants in the RCT will be 1,315 staff. The assignment ratio between experimental groups will be 2:2:1.

The sample size for the pre-post trial will be approximately 687 employees who will all receive the intervention.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Trial 1: Assuming a 5% significance level and 80% power, the RCT is powered to detect at least a 1.55 percentage point increase in the rate of participation by current non-givers in treatment as compared to those in pure control, and a 4.56 percentage point increase in treatment as compared to attention control. In addition, it is powered to detect a $0.19 increase in average fortnightly WG donation amount by current non-givers in treatment as compared to pure control, and a $0.17 increase in average fortnightly WG donation amount in treatment as compared to attention control. Trial 2: Assuming 5% significance and 80% power, the pre-post observational trial is powered to detect a clinically meaningful effect size of 0.23 percentage point change in WG participation by current non-givers as well as a 0.09 change in average WG donation amount per fortnight.
IRB Name
IRB Approval Date
IRB Approval Number
BETA ETH 2018 – 01
Analysis Plan

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Data Publication
Data Publication
Is public data available?
Program Files
Program Files
Reports, Papers & Other Materials
Relevant Paper(s)