Back to History Current Version

Reducing Absenteeism in the Workplace

Last registered on April 13, 2018


Trial Information

General Information

Reducing Absenteeism in the Workplace
Initial registration date
April 10, 2018

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
April 13, 2018, 11:08 AM EDT

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



Primary Investigator

University of Cologne

Other Primary Investigator(s)

PI Affiliation
University of Cologne
PI Affiliation
University of Cologne

Additional Trial Information

On going
Start date
End date
Secondary IDs
Excessive absenteeism in the workplace may affect workers’ productivity, firm’s financial output as well as team cohesion and perceived fairness. Yet, causal evidence on the effectiveness of potential instruments to reduce employee absence is scarce. We conduct a field experiment (RCT) in collaboration with a large German retail chain to investigate the effectiveness of two incentive schemes, randomly assigned among the firm’s apprentices. In particular, apprentices collect points throughout the year earning one point for each month without a single day of absence. At the end of the year, points are converted into a reward according to the randomly assigned treatment condition. One group of apprentices receives a monetary reward; another group receives a reward in the form of additional vacation days. The remaining apprentices serve as the control group. Treatments are designed to reduce those absence spells that are not due to genuine sickness, but are a form of shirking behaviour. The novelty of the time-off reward lies in the fact that it is in the same domain as the primary outcome. Therefore, it is less likely to backfire into excessive presenteeism. Along with a rich set of employee characteristics, we are able to observe the apprentices' daily attendance prior to, during and after the invention. We complement this dataset with two comprehensive surveys to investigate changes in the apprentices’ perception and to identify the corresponding mechanisms.
External Link(s)

Registration Citation

Alfitian, Jakob, Dirk Sliwka and Timo Vogelsang. 2018. "Reducing Absenteeism in the Workplace." AEA RCT Registry. April 13.
Former Citation
Alfitian, Jakob, Dirk Sliwka and Timo Vogelsang. 2018. "Reducing Absenteeism in the Workplace." AEA RCT Registry. April 13.
Experimental Details


We collaborate with a retail chain. Management in one region considered to implement a monetary attendance incentive, following the example of a comparable incentive scheme already in use in a different region. We offered to evaluate this instrument and proposed a variation that is not only novel to the academic literature, but may also reduce possible adverse effects associated with monetary incentives. The intervention takes place in a region. With the exception of final year apprentices, all of the firm's apprentices in the respective region participate in the experiment. The firm distinguishes between two different store types. For administrative reasons expressed by the firm, stores of type II are not eligible for one of the treatment conditions (treatment Time).
Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
Mean number of days absent due to sickness
Primary Outcomes (explanation)
The mean number of days absent due to sickness is standardized according to actual exposure.

Secondary Outcomes

Secondary Outcomes (end points)
Mean number of single day absences due to sickness
Mean length of absence spells
Secondary Outcomes (explanation)
The mean number of single day absences is standardized according to actual exposure.

Experimental Design

Experimental Design
There are three different treatment conditions, henceforth referred to as Time, Money and the control group. All apprentices receive a personal letter sent to their home address from the firm’s HR office. For apprentices in the control group, essentially nothing changes during the treatment. They are only made aware of a project called “Attendance Bonus” and that this project will be relevant to them at some later stage. Apprentices in the remaining two treatment groups are notified that they receive a “bonus point” for each month without a single day of absence due to sickness. The total duration of the experiment is twelve months. After every three months in the treatment period, the incentivized apprentices receive feedback on their current point score. However, bonus points are only transformed into actual rewards after the end of the experiment. Importantly, only the total number of accumulated points is payoff-relevant. The reward function is identical for both the Money and the Time condition. However, the two treatments differ with respect to the nature of the employed reward domain.

In the Time treatment, one reward unit corresponds to an extra holiday. A maximum number of four extra holidays can be achieved. The respective apprentices are granted their extra holidays two months after the end of the treatment period. From then on, the apprentice is free to choose when to make use of the additional holidays. Only store type I apprentices are eligible for the Time treatment for administrative reasons.

In the Money treatment, one reward unit corresponds to a bonus payment of €60. That is, a maximum bonus payment of €240 can be achieved. This conversion rate is chosen such that the values of a single reward unit are approximately equivalent for both reward domains. The respective apprentices receive their bonus payments in addition to their regular salary two months after the end of the treatment period.

Apprentices in the control group are not incentivized. Yet, they receive a notification prior to the beginning of the treatment period vaguely indicating that randomly chosen groups of apprentices will receive some sort of attendance contingent reward. Furthermore, they are notified that they will receive a comparable reward at a later point in time. In the context of the retail chain, informing the control group is inevitable, since apprentices in different treatment groups may yet attend the same vocational training school and thus exchange information. Therefore, informing those apprentices who are not incentivized that they are not systematically disadvantaged may prevent them from alternating their (attendance) behavior as an act of defiance.
Experimental Design Details
Randomization Method
Stratified Randomization
Randomization Unit
Treatments were assigned seperately for type I and type II stores, albeit following the same procedure.
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
315 Stores:
151 Type I Stores
164 Type II Stores
Sample size: planned number of observations
542 Apprentices: 268 Type I Store Apprentices 274 Type II Store Apprentices
Sample size (or number of clusters) by treatment arms
Time: 90
Money: 234
Control: 218
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Institutional Review Boards (IRBs)

IRB Name
IRB Approval Date
IRB Approval Number


Post Trial Information

Study Withdrawal

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

Request Information


Is the intervention completed?
Intervention Completion Date
December 31, 2018, 12:00 +00:00
Data Collection Complete
Data Collection Completion Date
March 16, 2020, 12:00 +00:00
Final Sample Size: Number of Clusters (Unit of Randomization)
232 stores
Was attrition correlated with treatment status?
Final Sample Size: Total Number of Observations
346 apprentices
Final Sample Size (or Number of Clusters) by Treatment Arms
149 apprentices (97 stores) control, 144 apprentices (101 stores) "Money"-treatment, 53 apprentices (34 stores) "Time"-treatment
Data Publication

Data Publication

Is public data available?

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Monetary incentives are widely used to align employee actions with employer objectives. We conducted a field experiment in a retail chain to evaluate whether an attendance bonus could reduce employee absenteeism. Apprentices in 232 stores were randomly assigned to a control group or one of two treatment groups in which a monetary or time-off attendance bonus was introduced for one year. We find that neither variant of the attendance bonus led to a systematic reduction in absenteeism. On the contrary, the monetary attendance bonus increased absenteeism substantially by around 50% on average, which corresponds to more than five additional days absent per employee and year. This effect was driven by the most recently hired apprentices. Survey results reveal that the monetary attendance bonus shifted the perception of absenteeism as acceptable behavior. The backfiring effect persisted beyond the end of the experiment, indicating a lasting erosion of social norms.
Jakob Alfitian, Dirk Sliwka, Timo Vogelsang (2023) When Bonuses Backfire: Evidence from the Workplace. Management Science 0(0).

Reports & Other Materials