Population Pyramid : Some Extensions and Enhancements

The paper presents some extensions to the population pyramid, which is a graphical technique used by demographers to visualize the age and sex distribution of a given population. The extensions to the plot include the visualization- when age intervals are unequal and comparison of age specific mortality rates for the different sexes are to be performed. A new plot, termed as the population cupola has been introduced. Concept of the bi-population pyramid and bi-cupola for visual comparison of age-sex distribution of two populations are the enhancements to the plot. Using intensity of grey scale in the pyramids, one can incorporate the age specific mortality rates for different sex- making the population pyramid more informative. Generalization of the pyramid and the cupola to three or more populations, in the form of star-pyramid and star-cupola are also stated