Discouraging Network-Based Hiring Without Compromising Productivity: Experimental Evidence from Low-Wage Workers in Pakistan

Last registered on August 11, 2025

Pre-Trial

Trial Information

General Information

Title
Discouraging Network-Based Hiring Without Compromising Productivity: Experimental Evidence from Low-Wage Workers in Pakistan
RCT ID
AEARCTR-0016460
Initial registration date
August 09, 2025

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
August 11, 2025, 10:12 AM EDT

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

Locations

Region

Primary Investigator

Affiliation
Lahore School of Economics

Other Primary Investigator(s)

PI Affiliation
University of Chicago

Additional Trial Information

Status
On going
Start date
2019-06-14
End date
2027-12-31
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
The majority of low-wage employment is found through social networks (Hofreiter and Banha, 2019). This reliance on personal connections for employment is even more vital in high-poverty settings, with 60-70% of individuals finding work through their networks in South and Southeast Asia (Witte, 2021). Economic theory proposes five mechanisms why employers favour hiring people they know.
In this study, we test which of the following mechanisms are at play:
a. Selection: Labourers who are connected to employers are, on average, more productive.
b. Asymmetric information: Employers have better information about the productivity of connected employees.
c. Match-specific productivity: Employees are more productive working for employers they are connected to.
d. Private utility from hiring: Employers reap private benefits from hiring those in their network.
e. Homophily: Employer effort on the job is less costly when employees are connected to other workers.
We test whether changing the incentives, information, and monitoring structures can increase the hiring of high-productivity or marginalised labourers.
Does a change in the hiring process impact labourers’ behaviour on the job (for example, by focusing more on productivity and less on maintaining their social connections with hiring managers)?
To investigate which of these mechanisms drives social network-based hiring, we have partnered with construction firms employing labourers on short-term contracts. We collect detailed hourly observations on the tasks completed by the labourer (e.g. the number of bricks placed and the volume of plaster mixed). We also conduct these observations with laborers whom we hire and who have not previously worked at the construction firm. In the experimental phase, we introduce three treatments: (i) providing managers with performance information of workers, (ii) offering incentives to managers for their team’s productivity, and (iii) varying managers' presence on site to monitor their teams. Our primary outcomes of interest are the team's average productivity and who gets hired, specifically the extent to which employers hire from their network.
External Link(s)

Registration Citation

Citation
Brown, Christina and Maryiam Haroon. 2025. "Discouraging Network-Based Hiring Without Compromising Productivity: Experimental Evidence from Low-Wage Workers in Pakistan." AEA RCT Registry. August 11. https://doi.org/10.1257/rct.16460-1.0
Experimental Details

Interventions

Intervention(s)
In the experimental phase, we introduce three treatment arms by randomly varying aspects of the manager-laborer interaction. The treatment arms are:
- Information treatment: For the subset of above-average productivity workers from baseline measurements, we will randomly select a subset of labourers and provide their names and contact information to managers, informing the manager that these were high-performing labourers. The information treatment is randomised at the manager- labourer level.
- Incentive treatment: Managers are provided with an incentive payment for their team’s average productivity for a given day. The incentive treatment is randomised at the manager-day location level.
- Monitoring treatment: We vary whether managers play a monitoring role for the team they hire on a given day. This is to be done by removing managers from the worksite and having their team monitored by a different manager. The monitoring treatment is randomised at the manager-day level.
Intervention Start Date
2019-06-14
Intervention End Date
2027-12-31

Primary Outcomes

Primary Outcomes (end points)
The study will understand the relevance of five mechanisms using the following primary outcomes:
Worker’s productivity on a given day
Hiring status (whether a worker is hired by the manager on a given day)
Primary Outcomes (explanation)
In order to quantify workers' productivity, we utilise a real-world setting where employers and laborers are doing their normal tasks. After a tremendous amount of piloting, we developed an laborer observation tool to collect detailed information for tasks on an hourly basis. Our productivity measure incorporates both the rate at which labourers complete their tasks and the total time spent at work each day, controlling for site-date level and a range of other sources of productivity shocks. Mainly, we measure workers’ output by the rate of bricks or tiles or blocks (and plaster) placed per minute times the total minutes spent working (end time – start time – breaks).

Secondary Outcomes

Secondary Outcomes (end points)
The study will also assess how the treatment condition influences the effort or time allocation, job search effort, and any resulting changes in their income.
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
We partnered with several major construction firms operating across urban and suburban areas of Lahore, Pakistan, employing hundreds of workers. As is typical in the construction and agriculture industries, these firms rely on managers (contractors) who act as intermediaries between the firm and the labourers. The managers are responsible for hiring, overseeing, and supervising the laborers. The laborers are hired on short-term, renewable contracts that typically last for a few days or weeks.
To identify potential construction firms for our study, we contacted the relevant government department and requested a list of construction firms involved in upcoming projects in Lahore. Firms were identified for selection if they had brick, tile, or block work (possible paintwork) for a significant number of months, operational sites in Lahore or its surrounding areas, hired workers on short-term contracts, and consented to allow observations and treatment roll-out on-site. All contractors and workers involved in brick, tile, block, and painting tasks are eligible to participate in the study.
The experiment is structured into two phases. In the first phase, we conduct laborers observations and surveys. The second phase involves the implementation of three treatment arms—information, incentive and monitoring. During the RCT phase, we continue to collect data through observations and surveys with labourers and managers.

Phase 1: Laborer Observation
First, we measure the daily productivity of labourers for on average three days on real tasks using a laborer observation tool developed by the research team. This includes a sample of labourers who have previously worked with the firm, along with labourers who are unknown to the hiring managers.

Phase 2: Information, Incentive and Monitoring Treatments:
Then, during the experimental phase, we introduce three treatment arms by randomly varying aspects of the manager-laborer interaction. In the information treatment, we share the names and contact information of a subset of above-average productivity workers with managers, informing the manager that these were high-performing labourer. The incentive treatment provides incentives to managers based on their team’s performance at a randomly selected location on a given day. Lastly, we implement monitoring treatment by varying whether managers play a monitoring role for their team.

To test five mechanisms, we collect data from three primary data collection exercises: labourer workday observations, labourer surveys, and manager surveys.
- Laborer workday observations: enumerators observe workers during the entirety of their day and record the tasks conducted and the output of that task on a minute-by-minute basis. This data allows us to have an accurate picture of laborers productivity. Laborer workday observations are conducted before and during the RCT phase.
- Laborer survey: Laborer surveys capture comprehensive information on worker demographics, employment, job search, contractual arrangements, supervisor monitoring, teammates, and social networks. Laborer surveys are conducted at the baseline and at the follow-up.
- Manager survey: We conduct a survey with managers to capture their beliefs about workers' productivity, the search process for labourers, social networks, and demographics.

Experimental Design Details
Not available
Randomization Method
The treatments were randomly assigned using a computer-generated number (except for a few pilot or initial rounds of some treatments).
Randomization Unit
Information treatment: The information treatment is randomised at the manager-labour level.
Incentive treatment: The incentive treatment is randomized at the manager-day level.
Monitoring treatment: The monitoring is randomized at the manager-day level.
Was the treatment clustered?
Yes

Experiment Characteristics

Sample size: planned number of clusters
Laborers: 1,700
Managers: 85
Sample size: planned number of observations
Laborers: 1,700 Managers: 85 Laborers Daily-Observation: 7,000
Sample size (or number of clusters) by treatment arms
Information Treatment: Laborers: 450 (Control: 150 and Treatment: 300)
Incentive Treatment: Observations Days: 740 (Control: 370 and Treatment: 370)
Monitoring Treatment: Observations Days: 100 (Control: 50 and Treatment: 50).
We will use different approaches to test for monitoring treatment arm. This will be a combination of randomly varying managers presence or using natural variation in managers presence on site. The sample will be based on which approach will be used. We expect that we have 100 manager days from treatment variation.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Given the sample specified, baseline-endline correlation, 3 pre-observations, 5 post-observations for the output outcome and 3 post-observations for the hiring outcome, using an ANCOVA and taking into account the treatment interaction structure (Muralidharan, Romero, and Wüthrich, 2022), we expect to detect the following effect sizes with power of 80% and alpha of 0.05. Effect size for hired: Information (0.13 sd), Incentive (0.16 sd), and Monitoring (0.17 sd) Effect size for output: Information (0.11 sd), Incentive (0.13 sd), and Monitoring (0.14 sd) We assume a 0.5 sample test correlation for the hired outcome using 200 units as the treatment and 800 control group. We use a 0.6 sample test correlation for the output using 200 units as the treatment and 800 control group.
IRB

Institutional Review Boards (IRBs)

IRB Name
The University of Chicago
IRB Approval Date
2024-02-02
IRB Approval Number
IRB22-0523