I would like to find the origin of the concept of the "demographic  
transition".  Who (and when) first used the phrase to refer to the  
idea that economic development would entail population going through  
a transition from high fertility and mortality but slow growth to low  
fertility and mortality also with slow growth after a period of rapid  
growth following mortality decline?  The earliest use I know of is  
Coale and Hoover in 1958.

Jeffrey Young