Top Demographers Question Gaza Mortality Study Citing Possible Double Counting and Method Flaws

Professor Sergio Della Pergola, a leading demographer and senior researcher at the Hebrew University of Jerusalem, has publicly challenged the reliability of a widely cited Gaza mortality study published in The Lancet Global Health. The original study estimated approximately 75,200 violent deaths during Israel's "Operation Sword of Iron" conflict in Gaza.

Together with independent researcher Dr. Mark Zeloczin, Della Pergola identified significant methodological issues undermining the study's population representativeness and casualty estimates. They noted that interviewers covered only small portions of their assigned areas, missing population distribution variability. They also raised concerns about potential double counting of deaths due to fragmented family reporting under wartime conditions. Furthermore, the original study did not report causes of death despite collecting such data.

Reanalysis of the publicly available data revealed unusual discrepancies among interviewers, with one team recording a quarter of all violent deaths despite surveying a tiny fraction of households. GPS navigation data indicated deviations from the declared sampling process, including repeated coverage of the same areas and interviews outside designated zones. The sampling teams primarily surveyed homes along main roads, largely excluding side streets. These irregularities were not addressed in the original mortality analysis.

Della Pergola emphasized that population-level mortality estimates depend on sample representativeness, which their review questions. They also highlighted discrepancies between the study's estimates of Gazans detained and independent arrest data. The researchers argue these findings warrant caution when interpreting the mortality figures from the Gaza conflict study.