Comparing the age structures of populations

This is an analytically simple note, motivated by the modest objective of presenting a visual aid to the scanning and comparison of the age structures of alternative populations. The means to the end are achieved by a graphical devise which is called a binary age comparison (or BAC) curve, which is obtained by plotting the cumulative age density function of one population against that of another within the unit square. The BAC curve allows a quick ascertainment of the unambiguous dominance of one population over another in terms of 'agedness', where such dominance obtains; and where thoroughgoing dominance does not obtain, it permits an assessment of the differentiated age structures, over different age segments, of a pair of populations.