Sex workers, Stigma and Self-Image: Evidence from Kolkata Brothels
Last registered on August 20, 2019


Trial Information
General Information
Sex workers, Stigma and Self-Image: Evidence from Kolkata Brothels
Initial registration date
August 19, 2019
Last updated
August 20, 2019 9:34 AM EDT
Primary Investigator
University of Glasgow
Other Primary Investigator(s)
PI Affiliation
King's College London
PI Affiliation
Indian Statistical Institute
PI Affiliation
University of Oxford
PI Affiliation
Durbar Foundation
Additional Trial Information
Start date
End date
Secondary IDs
This paper studies the link between self-image and behavior among those who face stigma due to poverty and social exclusion. Using a randomized field experiment with sex workers in Kolkata (India), we examine whether a psychological intervention aimed at mitigating the adverse effects of stigma can induce behavior change. We find significant improvements in participants’ self-image, as well as their savings and preventive health choices. Additionally, changes in savings and health behaviour persist up to fifteen and 21 months later respectively. Our findings highlight the potential of purely psychological interventions to improve the life choices and outcomes of marginalized groups.
External Link(s)
Registration Citation
Ghosal, Sayantan et al. 2019. "Sex workers, Stigma and Self-Image: Evidence from Kolkata Brothels." AEA RCT Registry. August 20.
Experimental Details
The intervention we evaluate was designed to improve the self-image of female sex workers living and working in red-light districts in the city of Kolkata, India. The intervention involved a training program that encouraged sex workers to re-examine their self-image in multiple ways. The program was developed and conducted by Durbar, a Kolkata-based NGO engaged in promoting the welfare of sex workers for over 25 years. It consisted of 8 weekly sessions with groups of sex workers (15-20 in each group), during which experienced trainers associated with the NGO attempted to reshape sex workers’ impaired self-image through interactive discussion, verbal persuasion and role-playing.
Intervention Start Date
Intervention End Date
Primary Outcomes
Primary Outcomes (end points)
Proxies of self-image: sense of shame, self-worth, ability to face challenges, comfort in public interaction
Other psychological variables: happiness, aspiration, decision-making power
Saving product choice: choice between current account or fixed deposits
Health-seeking behaviour: whether visited a doctor in clinic in the previous month
Primary Outcomes (explanation)
Secondary Outcomes
Secondary Outcomes (end points)
Bank account closures
Bank account balances
Secondary Outcomes (explanation)
Experimental Design
Experimental Design
Owing to greater interaction among sex workers within brothels rather than across, we randomised at the brothel level. We randomized two-thirds of the brothels (66 out of 98) into treatment after stratifying by brothel size. Next, to select sex workers within brothels for our study sample, we randomly surveyed between 50-70% of eligible sex workers across our three study localities, giving us a final baseline sample of 467 surveyed sex workers. All surveyed sex workers in treatment brothels were invited to participate in the training program, while those surveyed in the control brothels were not.

Participants in treatment groups gathered in groups of 15-20 in a room for the training session every week for 8 weeks. Each training session lasted about one hour, and the same group met in all sessions. All sessions of the training program were held in a pre-designated venue in each of the three study areas, except for the last session which was held at an offsite location. Each week’s training session was led by a different trainer, but within any given week, all groups were led by the same trainer.

At the end of each of the 8 weekly training sessions, we provided a token payment of Rs. 100 (approximately $ 1.41) to all program participants, and offered them two types of options on how they could receive this payment:

1. as an injection directly into their current account
2. as an injection to a fixed deposit, with or without a matching contribution from the participant, up to a specified amount limit.

Both these options were held with the sex workers’ cooperative bank, USHA. The (annual) interest rates on these products were 8% for current account balance, 12% on a fixed deposit without a matching contribution and 15% with such a contribution. These payments and the same menu of savings product options were offered to all participants in both the treatment and control groups. The control group participants were also required to meet at the same frequency as the treatment group, i.e. every week (in groups of approximately 20-25) for 8 weeks, to give us their savings choices.

In order to minimize the chances of spillovers among participants in the treatment group, whereby they could observe and mimic each other’s choices, we asked each participant to reveal her choice to us in a separate room after the completion of the training session. We also ensured that she was not able to return to the training room (where the remaining partici- pants from her group were sat) after having declared her choice. We followed similar protocol for the control group as well.
Experimental Design Details
Randomization Method
Randomization was done in office by a computer
Randomization Unit
Was the treatment clustered?
Experiment Characteristics
Sample size: planned number of clusters
98 brothels
Sample size: planned number of observations
467 sex workers
Sample size (or number of clusters) by treatment arms
66 treatment brothels and 32 control brothels
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB Name
Humanities and Social Sciences Research Ethics Committee, University of Warwick, UK
IRB Approval Date
IRB Approval Number
HSSREC 53/11-12
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 and Papers
Preliminary Reports
Relevant Papers