The Impact of Early-Life Access to Oral Polio Vaccines on Disability : Evidence from India

We evaluate the impact of oral polio vaccines on the incidence of all disabilities (locomotor, hearing, visual, speech and mental) in India, focusing on polio-related disability which constitutes the largest fraction of locomotor disabilities. Polio was hyperendemic in India even as recently as the early 1990s, but the country was declared wild polio virus-free in 2014. Average treatment effects on the treated from difference-in-differences with multiple time period models that condition on demographic and socio-economic characteristics reveal that with access to oral polio vaccines in the year of birth, the incidence of any disability, locomotor disability and polio-related disability declined by 20.5%, 11.6% and 7.2%, respectively, signaling substantial gains. We test for absence of pre-trends, and implement falsification tests and estimate alternate specifications to present robustness checks that offer support for these results. The eradication of polio in India, while relatively late, brought significant health benefits