Are Vaccination Campaigns Misinformed ? Experimental Evidence from COVID-19 in Low-and Middle-Income Countries

Routine immunization coverage estimated in surveys often substantially differs fromfigures reported in administrative records, presenting a dilemma for researchers and policy makers. Usinghigh-frequency phone surveys and administrative records from government sources in 36 low- and middle-income countries,this paper shows that such misalignment has also been common in the case of COVID-19. Across the sample, survey estimatesexceed administrative figures by 47 percent on average, at times suggesting markedly different policy conclusionsdepending on the data source consulted. This pattern is particularly stark and consistent in Sub-Saharan Africa. Toinvestigate the sources of this discrepancy, the paper presents results from six methodological experiments thatvary survey design choices and documents their effect on estimated COVID-19 vaccine coverage. The results show thatdesign choices matter, in particular the selection of respondents to be interviewed. However, phone surveyestimates prove remarkably robust to several commonly claimed biases. After accounting for observed errors ofrepresentation and measurement in the survey data, there remains a nonnegligible, unexplained residual gap withadministrative records. The paper provides indicative evidence of flaws and weaknesses in administrative datarecording and reporting that affect reported vaccination rates and could contribute to this gap. The findings matterfor past research on COVID-19 vaccination, future immunization efforts, and the design of robust dataproduction systems on health topics.