The city of Udaipur, in India’s north-western region of Rajasthan, is known as the “city of lakes”. Popular with tourists, it is built on the southern slopes of the Aravalli mountain range and is surrounded by sparsely populated and hard-to-access regions, where poverty and illiteracy remain widespread.

Udaipur, Rajasthan. Credit:Shutterstock

Since 1986, the Indian government has focused on establishing “non-formal education centres” to draw more children from such remote areas into the formal education system. These "informal schools" are typically run by non-government organisations, including Seva Mandir in the Rajasthan region. In 2003, this NGO, along with a team of economists - led by Esther Duflo, one of this week’s Nobel memorial prize in economics winners - set about tackling the widespread problem of teacher absenteeism in these remote schools.

The Nobel prize in economics has been awarded to Abhijit Banerjee, Esther Duflo and Michael Kremer "for their experimental approach to alleviating global poverty". Credit:AP

The researchers designed a “randomised control trial”, assigning schools to one of two groups: an intervention group and a "control" group, with about 50 schools in each group. Teachers in the intervention group were sent a camera with a tamper-proof date and time stamp. They were instructed to get a student to take a photo of themselves, and at least eight students, on both the morning and afternoon of each day they taught. As reward for their attendance, these teachers were paid their usual monthly salary of 1000 rupees, plus a bonus of 50 rupees for each additional day they taught above the standard 20 days. They were also fined 50 rupees a day for any of the 20 minimum days they skipped. The pictures provided the proof.