Crossovers that link populations with the same vital rates.
"In this paper, we consider crossovers of demographic density distributions from...populations that have the same fertility and mortality rates.  We focus on observed populations and their associated stationary and stable models, and on proportional distributions of persons, births, deaths and reproductive values.... Three different populations were selected to represent a range of demographic behavior.  Those populations are Japan 1963, a low mortality, low fertility population; Togo 1961, a high mortality, high fertility population; and the United States 1919-1921, a population whose fertility and mortality are intermediate."
D000349:Africa; D017954:Africa South of the Sahara; D000352:Africa, Northern; D000354:Africa, Western; D000569:Americas; D001208:Asia; D001519:Behavior; D003710:Demography; D019049:Developed Countries; D003906:Developing Countries; D005202:Asia, Eastern; D005298:Fertility; D005843:Geography; D007564:Japan; D008722:Methods; D008962:Models, Theoretical; D009026:Mortality; D009656:North America; D011153:Population; D011156:Population Density; D011157:Population Dynamics; D012106:Research; D014037:Togo; D014481:United States
Africa; Africa South Of The Sahara; Americas; Asia; Behavior; Demographic Factors; Developed Countries; Developing Countries; Eastern Asia; Fertility; French Speaking Africa; Geographic Factors; Japan; Methodological Studies; Models, Theoretical; Mortality; North America; Northern America; Population; Population Density; Population Dynamics; Research Methodology; Spatial Distribution; Togo; United States; Western Africa