There is no epidemiological or statistical result guaranteeing that the geometric center of case residences equals the source location. For a person-to-person contagious disease the spatial distribution of early cases is generated by (a) where susceptible hosts live and (b) the transmission process spreading outward and via commuting — so the “center” of the case cloud tracks the residential population’s geography, not the point of introduction. Two further weaknesses compound this: the specific estimator Worobey used, the coordinate-wise median, is not rotation-invariant, so the computed “center” depends on the arbitrary choice of coordinate axes; and Stoyan & Chiu’s bootstrap shows the market sits at the periphery of the centroid cloud while other landmarks (Wanda Plaza) are equally admissible centers. Therefore, even granting for argument that the market were the geometric center of the cases, that centrality would not imply it is the causal origin — centrality does not imply causality.
Validity verdict
status: approved; reason_if_not_false: checked.
The load-bearing move is a non-implication claim: “market is the geometric center of early cases” does not deductively entail “market is the causal origin.” Traced myself: the case cloud is generated by host residence geography plus the transmission process, none of which is pinned to the introduction point; there is no theorem mapping the centroid of an outward-spreading contagious process back onto its seed, so the entailment fails. The estimator points (non-rotation-invariance of the coordinate-wise median; market at the periphery of the bootstrap centroid cloud) are supporting, not load-bearing. The conclusion is deliberately scoped to “could not be inferred” (deduced), and does not overreach to “carries zero probabilistic evidence” — so no undercutting defeater applies. Holds as stated.