Rural Sociology Department
rural sociology, population shifts, population changes, census
There is more to population study than merely knowing how many people live in a geographical location. Two of the most important "other" aspects of demography are the age and sex composition of a population. Should planners be thinking about adding space to a grammar school or to a retirement center? By studying age and sex compositions, they will make more accurate decisions. The distribution of a population by age and sex is often shown in a pyramid. The bars in the pyramid (see inside) represent age groups spaced at 5-year intervals. The pyramid is also divided in the middle, with the males at the left and the females at the right. State pyramids for 1960, 1970, and 1975 point up interesting trends. One of the most significant is a lowered birth rate. Thus, the base of the pyramid reflecting the children is shrinking. Statewide services required for the very young may not need expansion. On the other hand, those born around 1960, when the birth rate was higher, are now young adults and form an exaggerated proportion of the state's population. Jobs and higher education are their major concerns. Should we build more colleges and technical schools to accommodate these young people? Look at the age structure at the bottom of the pyramid. In 10 years who is going to fill those schools? Perhaps educators should think in terms of temporary measures to alleviate present difficulties- extension courses, night classes, and the like. Population ratios and indexes like those under the "detailed state totals" can also be useful. Although pyramids are not portrayed, indexes and ratios as described below are provided for each county.
Agricultural Experiment Station, South Dakota State University
Riley, M P. and Zellner, W. W., "Population Update, Report Number 3" (1979). Agricultural Experiment Station Circulars. 231.