Working Paper: NBER ID: w30550
Authors: Seth M. Freedman; Daniel W. Sacks; Kosali I. Simon; Coady Wing
Abstract: We estimate direct and indirect vaccine effectiveness, and assess how far the infection-reducing externality extends from the vaccinated, a key input to policy decisions. Our empirical strategy uses nearly universal microdata from a single state and relies on the six-month delay between 12- and 11 year-old COVID vaccine eligibility. Vaccination reduces cases by 80 percent, the direct effect. This protection spills over to close contacts, producing a household-level indirect effect about half as large as the direct effect. However, indirect effects do not extend to schoolmates. Our results highlight vaccine reach as an important aspect of policy towards infectious disease.
Keywords: Vaccination; COVID-19; Indirect effects; Public health policy
JEL Codes: I00; I28
Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.
| Cause | Effect |
|---|---|
| Vaccination (I19) | COVID-19 cases among the vaccinated (I10) |
| Vaccination (I19) | Monthly COVID incidence for 12-year-olds (Y10) |
| Vaccination of a 12-year-old (J13) | COVID cases among household members (D19) |
| Vaccination of 12-year-olds (J13) | COVID incidence among adults living with vaccinated 12-year-olds (I12) |
| Vaccination (I19) | Indirect effects on COVID incidence (F69) |
| Increased vaccination among schoolmates (I24) | COVID incidence among sixth graders (A21) |