Possible effects of population pyramid

A population pyramid is just a graphical representation of the age and gender balance in a population at any given time. The shape of a population pyramid can reflect significant events which have happened to the society the pyramid depicts - for example the first world war left the population pyramid for the United Kingdom significantly dented on the male side because of the very large number of casualties among men of serving age. A population pyramid will show trends in childbirth, such as the 'baby boom' and the 'baby bust' in the sixties and seventies in the developed world. The shape of a pyramid will show whether a society is one where women have many or few children - for example a wide, shallow pyramid will show a population where people have large families and where there are high death rates. There are usually more women than men at the 'top' of the pyramid because women tend to live longer into old age.