Modest impact:
I have sometimes wondered whether the stabilization and occasional partial recovery of birth rates in rich countries was due to sophisticated assisted fertilization techniques. They now say (By the Numbers SCIENCE vol. 337 no. 6090 July 6, 2012 page 20 quoting International Committee Monitoring Assisted Reproductive Technologies) that there have been 5 million such births since 1978. Let’s say that is 3 million in the last 10 years or about 300,000 per year. If we add up the number of babies born last year in Australia, Austria, Belgium, Canada, France, Germany, Ireland, Italy, Japan, Netherlands, New Zealand, Norway, Poland , South Korea, Sweden, UK, US. all being populous and rich countries where if you want assisted reproduction you can probably afford it, (If I left out your favorite, not to worry; we are going for a minimum number here.) I make it to be over 10 million babies. (http://data.un.org/Data.aspx?d=SOWC&f=inID%3A75
UN data downloaded July 15, 2012) Maybe 3% of those were with medical assistance.
In Denmark the birth rate fell from about 12.2 per thousand in 2000 to about 10.3 per thousand in 2011 (CIA numbers http://www.indexmundi.com/g/g.aspx?v=25&c=da&l=en downloaded July 15, 2012) or about a 15% fall over that period of time. Assisted fertility appears to be significant, but hardly dominates things.
I must hasten to apologize if my statistics are inconsistent from one entry to the next. I do give references, but it seems to me that Denmark had been doing pretty well over the past few years, with low but steady fertility the last time I looked for numbers.
Anyway I am sticking by my crude back-of-the-envelope calculation. Assisted fertility does not dominate contemporary demographics either for good or for ill.
In contrast, a few years ago I looked at the numbers for France. At that time had assisted fertility been 100% effective instead of about 50%, France would have been just at equilibrium. So to me that means, “People don’t want babies,” doesn’t hold water. According to the same CIA web site (http://www.indexmundi.com/g/g.aspx?v=25&c=fr&l=en), which at least ought to be giving data that are internally fairly consistent, the birth rate in France has undergone some swings over the same 10 years.
Translating that into birth per woman according to the British Medical Journal: “The birth rate in France has also increased—from 1.88 children per woman of childbearing age in year 2000 to 1.89 last year.” (BMJ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1172030/ down loaded July 15, 2012) All right. That’s pretty close to replacement and in the ball park where assisted fertiilty may indeed be having an impact.
This does not lead us to any great eye opener. The big picture is unchanged. But it is nice to have a handle on the matter. Thank you International Committee Monitoring Assisted Reproductive Technologies. Keep up the good work.
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