Please fill out this short user survey of only 3 questions in order to help us improve the site. We appreciate your feedback!
Inefficiencies in The Transport Sector: Evidence from Liberia
Last registered on March 13, 2017


Trial Information
General Information
Inefficiencies in The Transport Sector: Evidence from Liberia
Initial registration date
March 10, 2017
Last updated
March 13, 2017 11:12 AM EDT
Primary Investigator
Columbia University
Other Primary Investigator(s)
Additional Trial Information
On going
Start date
End date
Secondary IDs
In Sub-Saharan Africa, intra-national transport costs are the highest in the world (World Bank 2009). The goal of this project is to understand how inefficiencies in the transport companies can explain these high transport costs. A major source of inefficiency in transport companies in Liberia seems to be a moral hazard where the agent is the truck driver and the principal is the manager. The company - and often the manager - owns the truck and takes the responsibility for delivering the services to the client. Meanwhile, the driver makes a set of decisions that will affect the output and that the firm cannot control. If the truck will have incentives to minimize his effort and to not take the action that will maximize the output. The actions the driver takes include the speed of the truck, the route taken and the number of breaks. These will all impact not only the quality of the service provided but also the costs incurred by the company, like fuel costs or repairs on the truck. In many developed countries, the firms monitor the drivers with GPS trackers. However, very few companies in Liberia use this technology. I am conducting a randomized control trial on transport companies in Liberia, among which I randomly select trucks to receive a GPS tracker. The system allows the manager to monitor the movements of the truck on his phone or computer. With this new technology the manager knows in real time where the driver is and is able to project more accurately when he will arrive at its destination.
External Link(s)
Registration Citation
de Rochambeau, Golvine. 2017. "Inefficiencies in The Transport Sector: Evidence from Liberia." AEA RCT Registry. March 13. https://doi.org/10.1257/rct.2049-1.0.
Former Citation
de Rochambeau, Golvine. 2017. "Inefficiencies in The Transport Sector: Evidence from Liberia." AEA RCT Registry. March 13. http://www.socialscienceregistry.org/trials/2049/history/14920.
Sponsors & Partners

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

Request Information
Experimental Details
I install GPS trackers on randomly selected trucks. The installation of the GPS tracker is done with the consent of the manager, and with knowledge of the driver. The GPS tracker is installed under the dashboard of the vehicle, connected directly to the battery of the truck. The GPS tracker sends a signal to a server that the manager can access from his or her phone (smartphone or not). The GPS tracker gives the location of the truck, but gives no information on the fuel consumption, oil levels, or any other pieces of information on the truck.
Intervention Start Date
Intervention End Date
Primary Outcomes
Primary Outcomes (end points)
The key outcome variables are anything that can measure the behavior of the driver: time it takes to complete a trip, distance covered, average speed of the truck, number of breaks taken in a trip, their length and the types of breaks, technical issues on the truck, maintenance costs, fuel costs. I also look at indirect variables, such as the structure of the contract of the driver (wage and bonus), the relationship between driver and driver (self-reported) and the commodities transported.
Primary Outcomes (explanation)
Secondary Outcomes
Secondary Outcomes (end points)
Secondary Outcomes (explanation)
Experimental Design
Experimental Design
Trucking companies in Liberia were recruited in the main transport hubs of the country. After baseline, trucks are randomly selected to receive a GPS tracker. The managers of trucks in the treatment are then contacted by our team of mechanics, who proceed to the installation of the GPS tracker. After installation of the GPS tracker, the manager is given access to the server so he can track the driver from his phone or computer.
Experimental Design Details
Randomization Method
Randomization done in office by a computer.
Randomization Unit
Each trucking company was randomly assigned a share of treated trucks. Inside each firm, each truck was randomly selected into the treatment group according to the share assigned to the company.
Was the treatment clustered?
Experiment Characteristics
Sample size: planned number of clusters
61 firms.
Sample size: planned number of observations
202 trucks.
Sample size (or number of clusters) by treatment arms
166 trucks in treatment group, 36 in control.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB Name
Columbia University MS IRB
IRB Approval Date
IRB Approval Number
Post Trial Information
Study Withdrawal
Is the intervention completed?
Is data collection complete?
Data Publication
Data Publication
Is public data available?
Program Files
Program Files
Reports, Papers & Other Materials
Relevant Paper(s)