A comment on glenn Firebaugh’s “population density and fertility”

Firebaugh has attempted to test an interesting, if counterintuitive, theory. I have argued that his empirical model is incompletely specified, and that one should reserve judgement on his hypothesis until a better means of testing it can be developed. In particular, the use of ratio variables and pooled data create substantial statistical problems.f The simultaneous responses of the CBR and village population size to outside-of-model variation yield an inflated estimate of the effect of population density on fertility.