Long-term direct and spillover effects of early childhood immunization

Abstract

This paper investigates the long-term direct and spillover effects of an early childhood immunization program. By exploiting quasi-experimental variation from a national immunization program targeting children under the age of one in China, we apply a difference-in-differences approach to estimate its long-term impact. Using data from the China Family Panel Studies, we find significant long-term health benefits among children born during or after the program's implementation. Moreover, we observe educational spillover benefits for older siblings of age-eligible children, particularly when the older siblings are male or were younger at the time of the eligible child's birth. These spillover effects diminish as the number of siblings in the household increases. Our findings suggest that the presence of an age-eligible child influences their siblings' outcomes, in part, through intrahousehold resource allocation.