Old Delhi is dense. The lanes are narrow. The schools — government and private — sit within walking distance of each other, sometimes on the same street. Families have choices. The question is what shapes those choices when the child is a girl.
In 2010, we designed what became India’s first randomised controlled trial on school vouchers for girls’ education. The design was simple: give randomly selected families a voucher that covered the fees at a private school of their choice. Measure whether enrolment patterns changed.
The hypothesis was that the barrier was cost. If private schools were already trusted (and in Old Delhi, they were — for complex reasons involving language of instruction, perceived teacher quality, and social aspiration), then a voucher that removed the fee barrier should increase girls’ private school enrolment.
The design
The randomisation was at the household level. Families were identified through door-to-door surveys in specific Old Delhi wards. Treatment families received a voucher; control families did not. Both groups were tracked over the school year.
The trial was early. In 2010, randomised evaluations of education policy in India were uncommon. The methodological infrastructure — survey teams trained in RCT protocols, consent processes calibrated for low-literacy populations, data systems that could track individual students across school types — had to be built alongside the study itself.
What we learned
The answer was more complicated than “yes, cost is the barrier.”
Cost mattered. Families who received the voucher were more likely to enrol their daughters in private schools. The price signal was real: when the fee disappeared, behaviour changed.
But cost was intertwined with other factors that the voucher alone could not address. Some families used the voucher and then withdrew the girl mid-year because the private school’s schedule conflicted with domestic responsibilities. Some families enrolled the girl but kept the boy in government school — the voucher created a within-household allocation decision that the design had not anticipated.
The most interesting finding was about information. Some families in the control group, who did not receive a voucher, nevertheless changed their school choice during the study period — because the survey process itself had prompted conversations about schooling that the family had not previously had. The act of being asked “which school does your daughter attend, and why?” was itself an intervention.
What this means for RCTs
The study taught us to be honest about what an RCT can and cannot tell you.
An RCT can tell you whether a specific intervention (a voucher) causes a specific outcome (enrolment in private school) on average across the treatment group. That is valuable. It is evidence of a kind that observational studies cannot provide.
But the averages hide the households. The family that used the voucher for the daughter but pulled her out in October. The family that enrolled the daughter and saw her grades improve but could not afford the uniform. The family that never used the voucher because the mother-in-law decided the government school was good enough.
These are not statistical noise. They are the lived texture of the intervention — and they are what a programme designer needs to see in order to make the voucher work better the next time.
The gender lens
The trial was specifically about girls. This was a deliberate design choice, and it shaped everything from the sampling frame to the household survey to the analysis plan.
Girls’ schooling in Old Delhi operates within a set of constraints that boys’ schooling does not: safety concerns about walking to school, early withdrawal for marriage preparation, household labour demands that compete with school hours, and family decisions about which child is “worth” the investment of a private school fee.
A voucher addresses the fee constraint. It does not address the safety constraint, the labour constraint, or the marriage constraint. The trial showed that cost is a necessary condition for girls’ private school enrolment but not a sufficient one. The other constraints need different interventions — and they need to be studied on their own terms, not assumed away by a programme that says “give them a voucher and the problem is solved.”
This is the thread through all the measurement work: the indicator you choose shapes what you see. An enrolment number tells you the girl is in school. It does not tell you if she is staying, learning, or free to choose.