HARMLESS OMISSION IN THE STANDARDIZATION OF DEMOGRAPHIC RATES

Standardization is a well-known technique used to avoid compositional effects when schedules of demographic rates are compared for two or mo re subpopulations. Common sense tells us that such standardization can be omitted when the subpopulations have the same structure with respe ct to the covariates one could standardize for. The present paper give s a theoretical justification of this intuitive insight and relates it to the theory for harmless model mis-specification in intensity-regre ssion analysis. The idea of the latter notion is that under certain ci rcumstances one can omit factors without producing biases which affect the coefficients of remaining covariates, even when the omitted facto rs genuinely affect the investigated behavior.