Constructing Africa’s Cities: Construction workers and conscientiousness training in Dakar Senegal

Last registered on December 22, 2021


Trial Information

General Information

Constructing Africa’s Cities: Construction workers and conscientiousness training in Dakar Senegal
Initial registration date
March 22, 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
March 23, 2019, 8:28 PM EDT

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

Last updated
December 22, 2021, 10:58 AM EST

Last updated is the most recent time when changes to the trial's registration were published.



Primary Investigator

Trinity College Dublin

Other Primary Investigator(s)

PI Affiliation
DIME, World Bank
PI Affiliation
Trinity College Dublin

Additional Trial Information

On going
Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Rapid population growth is a key development challenge facing the African continent in the coming decades. Africa’s population, which currently stands at 1.19 billion, is set to grow to 1.63 billion by 2030. This will place huge demands on many sectors of the economy and raises major concerns about how to provide jobs and livelihoods for Africa’s youth. Rapid population growth and urbanization is also placing substantial demands on Africa’s infrastructure with major investments in public infrastructure, including transport, telecommunications and public housing, crucially needed. The labor-intensive nature of such projects provides an opportunity for job creation in the sector, which is one of the main sectors of employment for young men. The central question underlying this project is whether the value of jobs created in large transportation infrastructure investments can be improved by training workers on key non-cognitive skills known to be positively associated with a range of labor market outcomes.

The setting for our project is Dakar, Senegal. The Government of Senegal (GoS) has recognized that improving urban mobility in the Greater Dakar Area (GDA) is of crucial importance for the development of the Senegalese economy, and it has adopted a comprehensive 5-year plan to address some of the challenges that the sector faces. A key flagship projects of this plan, with strong presidential support, is the development of a railway express line (TER) linking the city centre to the south of the city.

The TER began construction in 2017, although construction and hiring of construction workers did not ramp up until beginning of 2018. Currently there are 1061 workers employed in the construction of the TER of which 938 are non-technical workers (in the office or at the construction site), and of these 208 workers are considered unskilled. Additional hiring will occur throughout this year as more workers are required to ensure that the TER is completed by January 2019. Additional workers will especially be required for various complementary construction projects related to building the supporting infrastructure of the TER such as the building of bridges and tunnels.

Our aim to study whether the value of the jobs created by this project can be augmented by a complementary training intervention. Specifically, we will explore the whether a short training programme on non-cognitive skills (conscientiousness) can improve labor market outcomes during the construction of the TER and after the end of the infrastructure construction.

Our project will contribute to three key strands of academic literature. First, we contribute to the broader literature examining the impact of transportation investments on welfare since while job creation is cited as a benefit of these projects, there has been no in-depth examination of this claim. Second, we will contribute to the literature on the impact of worker training considering the dynamic impacts of training beyond the lifecycle of the contract. Third, we will add to the small but growing literature on the role of non-cognitive skills for workers. The results of this impact evaluation will directly inform policy makers in Senegal and in other countries on how to increase the short and medium-term benefits that arise through complementary investments in the construction sector which is relevant to transport and infrastructure projects more generally.
External Link(s)

Registration Citation

Kirchberger, Martina, Sveta Milusheva and Carol Newman. 2021. "Constructing Africa’s Cities: Construction workers and conscientiousness training in Dakar Senegal." AEA RCT Registry. December 22.
Former Citation
Kirchberger, Martina, Sveta Milusheva and Carol Newman. 2021. "Constructing Africa’s Cities: Construction workers and conscientiousness training in Dakar Senegal." AEA RCT Registry. December 22.
Experimental Details


For this pilot study, we will work directly with Eiffage, the main company responsible for constructing the TER. The intervention will be the provision of training in non-cognitive skills that have been identified as important by Eiffage for low-skilled construction jobs. We will focus on unskilled workers engaged in tasks that require no technical skills but so require that workers are conscientious, attentive, good communicators and strictly adhere to rules for security and safety reasons. The intervention will involve one group session with the workers allocated to the treatment group where issues around safety and conscientiousness will be discussed. Each worker will be called once per week for the following eight weeks with reminders in to be conscientious in the work place.
Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
We will examine whether providing non-cognitive skills leads to improved outcomes on-the-job but also for workers in their future employment. Outcomes will be worker performance, worker retention, wage, promotion, job satisfaction, whether the worker finds subsequent employment once the current contract ends, the length of time it takes to find a new job, wage at the time of commencing a new job, job satisfaction at new job.
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
There are approximately 400 unskilled workers employed by Eiffage in the construction of the TER. 200 individuals will be randomly assigned to the treatment group and 200 to the control group. All workers will be surveyed at baseline and endline.
Experimental Design Details
Randomization Method
The workers are randomly assigned to either the treatment or the control group with approximately 200 workers in each group.
Randomization Unit
The unit of randomization is the worker (individual).
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
Not applicable
Sample size: planned number of observations
Sample size (or number of clusters) by treatment arms
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
For the power calculations we rely on work by Hudson and Fraley (2015) which involved students writing down their goals for improving certain personality traits (including conscientiousness) weekly. This study found a monthly increase in conscientiousness of 0.05 standard deviations, which would mean an increase of 0.15 over 3 months. Other studies found increases of 0.19 standard deviations (Roberts et al., 2017). As such, we base our power calculations on a minimum detectable effect size of 0.17. In the absence of a measure of conscientiousness for our particular population of construction workers in Senegal, we use the Hudson and Farley (2015) study average conscientiousness level of 3.4 and standard deviation of 0.62 for our power calculations. We will have both baseline and endline data. We assume a correlation between the two of 0.8 since data will be collected on the same individuals within a 3-month period and we expect personality traits to be persistent over time. With an alpha of 0.05, 200 individuals in the treatment group and 200 individuals in the control, and a minimum detectable effect size of 0.19, we achieve power of 86.5%.

Institutional Review Boards (IRBs)

IRB Name
Faculty of Arts, Humanities and Social Sciences, Research Ethics Committee, Trinity College Dublin
IRB Approval Date
IRB Approval Number


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