What is the magnitude of the subpopulation effect?

What is the magnitude of the subpopulation effect?

The effect of population subdivision on estimated match probabilities has been raised Nature 339 (1989) 501; Am. J. Hum. Genet. 48 (1991) 819; Science 254 (1991) 1921]. Previous work J. Forensic Sci. 39 (1994) 319; J. Forensic Sci. 39 (1994) 988; Am. J. Hum. Genet. 55 (1994) 533] has compared product rule estimates from differing databases and found that the "subpopulation" error may be of the order of a factor of 10. This approach compares an estimate with an estimate. This paper uses simulation to extend these studies by allowing a comparison to a 'true match probability' and supports the conclusion that subpopulation effects are mild. In addition the performance of recommendations 4.1 and 4.2 of NRC II National Research Council and C.O.D.F. Science, The Evaluation of Forensic DNA Evidence, National Academy Press, Washington, DC, 1996].