Editing Demographic transition (section)

=== United States ===
Greenwood and Seshadri (2002) show that from 1800 to 1940 there was a [[demographic shift]] from a mostly rural US population with high fertility, with an average of seven children born per white woman, to a minority (43%) rural population with low fertility, with an average of two births per white woman. This shift resulted from technological progress. A sixfold increase in real wages made children more expensive in terms of forgone opportunities to work and increases in agricultural productivity reduced rural demand for labor, a substantial portion of which traditionally had been performed by children in farm families.<ref>{{Cite journal|title=The U.S. Demographic Transition|last1=Greenwood |first1=Jeremy |last2=Seshadri |first2=Ananth|date=January 2002|ssrn = 297952}}</ref>

A simplification of the DTM theory proposes an initial decline in mortality followed by a later drop in fertility. The changing demographics of the U.S. in the last two centuries did not parallel this model. Beginning around 1800, there was a sharp fertility decline; at this time, an average woman usually produced seven births per lifetime, but by 1900 this number had dropped to nearly four. A mortality decline was not observed in the U.S. until almost 1900—a hundred years after the drop in fertility.

However, this late decline occurred from a very low initial level. During the 17th and 18th centuries, crude death rates in much of colonial North America ranged from 15 to 25 deaths per 1000 residents per year<ref>{{cite book|title=A Population History of the United States|author= Herbert S. Klein|page=39}}</ref><ref>{{cite book|title=A Population History of North America|author1= Michael R. Haines |author2=Richard H. Steckel|pages=163–164}}</ref> (levels of up to 40 per 1000 being typical during stages one and two). Life expectancy at birth was on the order of 40 and, in some places, reached 50, and a resident of 18th century Philadelphia who reached age 20 could have expected, on average, additional 40 years of life.

This phenomenon is explained by the pattern of colonization of the United States. Sparsely populated interior of the country allowed ample room to accommodate all the "excess" people, counteracting mechanisms (spread of communicable diseases due to overcrowding, low real wages and insufficient calories per capita due to the limited amount of available agricultural land) which led to high mortality in the Old World. With low mortality but stage 1 birth rates, the United States necessarily experienced exponential population growth (from less than 4 million people in 1790, to 23 million in 1850, to 76 million in 1900).

The only area where this pattern did not hold was the American South. High prevalence of deadly endemic diseases such as malaria kept mortality as high as 45–50 per 1000 residents per year in 18th century North Carolina. In [[New Orleans]], mortality remained so high (mainly due to [[yellow fever]]) that the city was characterized as the "death capital of the United States" – at the level of 50 per 1000 population or higher – well into the second half of the 19th century.<ref>{{cite journal |first=Michael R. |last=Haines |title=The Urban Mortality Transition in the United States, 1800–1940 |journal=NBER Historical Working Paper No. 134 |date=July 2001 |doi=10.3386/h0134 |doi-access=free }}</ref>

Today, the U.S. is recognized as having both low fertility and mortality rates. Specifically, birth rates stand at 14 per 1000 per year and death rates at 8 per 1000 per year.<ref>{{Citation | url = https://www.cia.gov/the-world-factbook/countries/united-states/ | title = World factbook | date = 17 November 2021 | contribution = US | publisher = CIA | place = USA}}.</ref>