Table 2. Impact of supplementary immunization activities (SIAs) on routine vaccinations—instrumental variable (IV) results.
| (1) | (2) | (3) | (4) | (5) | |
|---|---|---|---|---|---|
| Bangladesh | Senegal | Togo | Gambia | Cote d'Ivoire | |
| Panel A: FIRST STAGE | |||||
| Dependent variable: SIA exposure | |||||
| Age at first campaign | -0.037*** | -0.146*** | -0.099*** | -0.447*** | -0.417*** |
| (0.001) | (0.005) | (0.002) | (0.010) | (0.014) | |
| F-statistic of age at first campaign | 54.95 | 86.86 | 63.46 | 718.39 | 1058.54 |
| Panel B: SECOND STAGE | |||||
| Dependent variable: Has DPT 3 + Measles + BCG | |||||
| SIA exposure | -0.055** | -0.013** | -0.036** | -0.003 | -0.006 |
| (0.022) | (0.006) | (0.015) | (0.008) | (0.011) | |
| Mean SIA exposure in sample | 5.228 | 4.505 | 4.769 | 3.762 | 9.856 |
| Observations | 12,190 | 14,817 | 6,659 | 3,342 | 3,106 |
Robust standard errors in parentheses.
*** p<0.01,
** p<0.05,
*
p<0.1. All models control for rural residence, birth order, mother's educational level (primary, secondary or higher), household electricity, sex (female), birth in rainy season, and fixed effects for survey round and birth year. See Table B in S1 File for full regression results (including control variables). The sample includes children aged 12–59 months. Standard errors are adjusted for clustering within survey-specific regions.