Stoyan & Chiu reconstruct Worobey et al.’s Monte Carlo procedure (1,000 inhomogeneous-Poisson simulations with intensity proportional to residential population density) and compute the p-value for the market being the “center” of the early-case cloud under three center definitions and four case subset sizes.

Center definitionn=155n=150n=100n=80
Centroid (mean)0.0300.0240.0600.122
Center-point0.0080.0090.0430.068
Mode0.0700.0720.1550.200

Significance is at best marginal at the full sample and disappears as the sample is trimmed, showing the market-as-center result is not robust. (Worobey’s own reported median market-to-case distance for the 155 cases was 16.11 km.)