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Training in call centres

Last registered on November 04, 2019


Trial Information

General Information

Training in call centres
Initial registration date
October 31, 2019

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
November 04, 2019, 10:20 AM EST

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



Primary Investigator

IFAU Uppsala

Other Primary Investigator(s)

Additional Trial Information

Start date
End date
Secondary IDs
This RCT analyses the effects of a week-long training program on workers' productivity. Agents working in the largest department of the call centre of a multinational telecommunication company are randomly assigned to treatment and control groups.
External Link(s)

Registration Citation

Sauermann, Jan. 2019. "Training in call centres." AEA RCT Registry. November 04.
Experimental Details


The intervention included a week-long training intervention targeted at call agents in the largest department of the call centre. The aim of the training programme was to increase the efficiency of agents answering customer calls. The management decided to organise the training in order to decrease the average time needed for handling calls, because the call centre performed below the targets set.

Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
Worker productivity (as measured by average handling time)
Primary Outcomes (explanation)
Worker productivity is defined as the inverse of average handling time: y=100/(average handling time in week t measured in seconds)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
Out of the 157 individuals working in the department at the beginning of our observation period (week 50/2008), 86 were selected for the experiment. Conditional on being selected for participation in the field experiment, 37 out of the 86 agents were randomly selected for participation in the treatment group. The remaining 49 agents who were assigned to the control group were trained after the post-experiment period.

Agents assigned to participate in the fi eld experiment were randomly assigned to be treated during the treatment period, or to be treated after the end of the experiment. Due to the restriction that agents should be trained with other agents from the same team, half of the teams were randomly assigned to the treatment group, whereas the other half was assigned to the control group. Each team was then randomly split up in di fferent training groups, due to size constraints of the training centre.
Experimental Design Details
Randomization Method
Randomization was done on the PI's office computer
Randomization Unit
Main randomization unit: team; secondly: agents of teams were randomly assigned to training groups
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
10 teams
Sample size: planned number of observations
86 agents selected for the experiment
Sample size (or number of clusters) by treatment arms
3 treatment; 3 controls
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

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Is the intervention completed?
Intervention Completion Date
September 30, 2009, 12:00 +00:00
Data Collection Complete
Data Collection Completion Date
October 31, 2009, 12:00 +00:00
Final Sample Size: Number of Clusters (Unit of Randomization)
74 workers
Was attrition correlated with treatment status?
Final Sample Size: Total Number of Observations
Final Sample Size (or Number of Clusters) by Treatment Arms
34 control, 40 treatment
Data Publication

Data Publication

Is public data available?

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

This paper analyses the effects of work-related training on worker productivity. To identify the causal effects from training, we combine a field experiment that randomly assigns workers to treatment and control groups with panel data on individual worker performance before and after training. We find that participation in the training programme leads to a 10 percent increase in performance. Moreover, we provide experimental evidence for externalities from treated workers on their untreated teammates: An increase of 10 percentage points in the share of treated peers leads to a performance increase of 0.51 percent. We provide evidence that the estimated effects are causal and not the result of employee selection into and out of training. Furthermore, we find that the performance increase in not due to lower quality provided by the worker.
Andries De Grip, Jan Sauermann (2012), "The Effects of Training on Own and Co-Worker Productivity: Evidence from a Field Experiment", Economic Journal, 122(560), pp. 376-399.
Do reciprocal workers have higher returns to employer-sponsored training? Using a field experiment with random assignment to training combined with survey information on workers' reciprocal inclinations, the results show that reciprocal workers reciprocate employers' training investments by higher posttraining performance. This result, which is robust to controlling for observed personality traits and worker fixed effects, suggests that individuals reciprocate the firm's human capital investment with higher effort, in line with theoretical models on gift exchange in the workplace. This finding provides an alternative rationale to explain firm training investments even with the risk of poaching.
Sauermann, J. (2023). Worker reciprocity and the returns to training: Evidence from a field experiment. Journal of Economics & Management Strategy, 32, 543–557.
We assess selection bias in estimated returns to workplace training by exploiting a field experiment with random assignment of workers to a one-week training program. We compare experimental estimates of this program with non-experimental estimates that are estimated by using a sample of agents who were selected by management not to participate in the experiment. Our results show that non-experimental estimates are biased, yielding returns about twice as large as the causal effect. When controlling for pre-treatment performance or individual fixed effects, only about one tenth of this bias remains and is even further reduced when applying common support restrictions.
Sauermann, Jan, and Anders Stenberg, "Assessing Selection Bias in Non-experimental Estimates of the Returns to Workplace Training", IZA DP No. 13789]

Reports & Other Materials