Offering free eyeglasses to poor students increases their test scores.
By S.H. | LONDON
IN PARTS of the world where designer eyewear products are popular, it is sometimes easy to forget the problems that people with poor vision and limited means face in many developing countries. A study of some 20,000 children in rural China, for instance, found that 24% of primary school students suffered from reduced uncorrected vision in either eye and 16% in both eyes. Many impoverished children would benefit from—but are not—wearing glasses. Sometimes parents are not aware of their kids’ poor eyesight, and at other times they suffer from credit constraints. One may therefore ask: could provision of free eyewear promote development? Economists Paul Glewwe, Albert Park and Meng Zhao think so. In a recent paper they describe how offering poor children glasses at no cost led to vastly improved educational outcomes.
The three researchers studied the results of a government-sponsored field experiment carried out in western China. Thirty-seven townships in the province of Gansu participated. About three fourths of the province’s population live in rural areas and are among the poorest in China. Some 250 primary schools were divided into two groups according to townships; schools in 19 townships were assigned to a programme that provided free eyeglasses to low-income students and schools in 18 townships were assigned to a control group that did not benefit from the programme. Students in grades 4-6 who were found to have poor vision were offered glasses at no cost.
A year after the programme was introduced, the academic performance of the students in the two groups was measured. The authors found that among the students with poor vision, those who were offered free glasses enjoyed an improvement in test scores equivalent to 0.3 years of additional schooling. However, many students turned down the offer to receive free glasses (some parents objected whereas female students in particular did not want to wear glasses), so the researchers also looked at the effect only among the students who accepted the offer to get a pair of eyeglasses at no cost. Naturally, the effect was even larger, equivalent to the increase in test scores associated with 0.9 years of extra schooling. In other words, offering poor students free eyeglasses and making sure that they accept the offer had close to the same positive impact on the students' test scores as putting them through a whole additional year of school.
Unsurprisingly, the researchers found in a cost-benefit analysis that the programme paid off handsomely. Using the most conservative estimate of the impact of schooling on wages and the lower of the two aforementioned figures on the effect of the free-glasses programme on test scores, they conclude that the experiment increased an average middle-school graduate’s annual income by at least 128 yuan per year, which exceeded the cost of a pair of glasses.
This seems like the typical low-hanging fruit that international development policy would benefit from.
