Historical change in the large-scale population distribution of the United States

Measures of central tendency and dispersion are the mainstay of statistical description. Their spatial analogues can be used to describe geographic distributions, and here they are employed to describe the historical path of the large-scale spatial distribution of the US population. The azimuthal equidistant projection and a three-dimensional coordinate approach are used to describe centrality, and Bachi's standard distance, and the standard deviational ellipse are used to describe dispersion. Other measures are used to describe demographic features such as differences in population density, and the degree to which the population distribution has become bicoastal. Decennial US Census data for the period 1790–2010 is combined with novel use of several measures. The analysis reveals that both the dispersion of the population and the growth of coastal populations has slowed dramatically during the last few decades. In addition to implications for changes in the demand for services such as housing and health care, the results suggest that the geographic distribution of the US population is reaching, at least temporarily, a mature equilibrium characterized by slower changes.