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USA improves disease control

New Scientist magazine (13 October 2012, page 7) notes that the US's fertility rate has declined to 1.9 children per woman of child bearing age in 2011, down from 2.1 in 2008.  This is the average for a woman during her lifetime if the average fertility rate for the year applied.

The article was based on a report published by the US Center for Disease Control and Prevention.

Perhaps they are trumpeting their success!

A fertility rate of 1.9 is below replacement, meaning that if that rate applied for a very long time, the population would decrease in the absence of positive net migration.  In practice, births still exceed deaths by a large margin because life expectancy is increasing and there are a lot more people producing children than are old enough to have a high mortality rate and will be for decades.

The US Center for Disease Control and Prevention still has a lot of work to do!


Charlie Nelson
October 2012