You may benefit from clarification on the differences between crude birth rate, general fertility rate and total fertility rate. Carl Haub’s recent blog will accomplish this.
Reports That the U.S. Birth Rate in 2011 Was the Lowest in History Are, Well, Wrong
(November 2012) Several newspapers, blogs, and websites have proclaimed that the U.S. “birth rate” in 2011 was the lowest since records have been kept. But it wasn’t. The number that various sources have been calling the “birth rate” is actually the general fertility rate—that one was the lowest ever. Not the total fertility rate, which is the correct measure to use. Let me explain!
The term “birth rate” is loosely used to mean one of three commonly used measures, which demography refers to as fertility. The crude birth rate is annual births per 1,000 total population; the general fertility rate is annual births per 1,000 women of childbearing age; and the total fertility rate is the average number of children women would bear in their lifetimes if the pace of childbearing remained constant for the long term.
What is right: The preliminary report by the U.S. National Center for Health Statistics noted that the general fertility rate (GFR) of 63.2 for 2011 was the lowest ever reported. In fact, the crude birth rate (CBR) of 12.7 was also the lowest ever. But neither is the best way to capture the birth rate. Why? Because both of these measures are affected by age structure.
To read the full article, please click here: http://prbblog.org/index.php/2012/11/28/reports-that-the-u-s-birth-rate-in-2011-was-the-lowest-in-history-are-well-wrong/