Earlier this morning I read this intriguing paper by US researchers Robert Drago & Amy Varner. The title of the paper is “Fertility and Work in the United States: A Policy Perspective” and it addresses the important issues of gender equality and the historical trend towards declining fertility in the United States. Now while I was thinking of how to write a post on this general topic I wandered over to Brad Delong’s blog and found he had this highly relevant post entitled MenarchÃ© vs Monarchy.
OK, what’s this all about.
Well………. before we can go much further we need to touch on one of the important underlying reasons for the really low low-fertility levels (below 1.5 TFRs) that we can now find in many OECD countries: the so-called tempo effect. (Rather than belabouring the reader too much here, I have just put up a post on my own blog which has a little more detail and argument on the tempo effect and it’s consequences, and you can also see it identified in slide 18 in this presentation, which is dealt with in this post and its comments).
Basically fertility hits extremely low levels due to a displacement upwards in the age of having children. The reasons for this are various (a consumer society would be one of them, need to earn and save enough to purchase a home might be another) and rising education needs for women in an information economy would certainly be another. The problem is, in order to improve our fertility we need to address this trend, and to try, if possible, to encourage women to have children at a younger age. This is entirely amenable to being argued in policy terms on a social interest basis, but the really, really interesting point that Drago and Varner stress is that this is also in the interest of the woman who wants to have children.
If you like ppt presentations demographer TomÃ¡s Sobotka has a very interesting presentation about these sort of issues here.
Most of the studies indicate that women on average wish to have two children. Unfortunately, like many wishes, this one does’t convert itself into reality. The big question is why not?
Well one of the issues is fertility – in the biological sense of reproductivity. There is a window of fertile opportunity, with a peak age of fertility, and past this age things get more and more difficult. Without apologies I quote Drago and Varner at length, since I think this issue is generally poorly understood:
“It is well known that, over long periods of time, as a nation becomes more affluent, average family size shrinks due to a reduction in rates of childbearing….What is less well known and little studied is the related phenomenon of delayed childbearing. That is, the reductions in fertility just mentioned have occurred in conjunction with a more recent upward shift in the ages at which women bear children. The implications of delayed childbearing are more complex. On the one hand, recent medical advances provide many women with the opportunity to ‘sequence’, and achieve career success prior to the raising of children. For many career women in earlier times, this option was not available and so they were often forced to remain childless in order to stay on a career track. On the other hand, the risks associated with delayed childbearing are not, in our opinion, widely known. We document those risks below. If women and men were aware of the risks surrounding attempts to delay childbearing, it is possible that many would seek to bear children at an earlier age.”
“We consider three sets of medical issues related to delayed childbearing below: risks to the mother, risks to the child, and infertility treatments. The latter are not strictly associated with delayed childbearing, although the risk of infertility rises with the age of the prospective mother, leading us to cover the issue here…..There are various maternal risks associated with childbearing. However, as the prospective mother’s age increases, there is a dramatic increase in the likelihood of childbearing complications…..First, the probability of carrying a child to term is significantly reduced after the age of 35…..There are several fetal risks associated with advanced maternal age. In a study of 379 mature prospective mothers, age 35 years and older, in comparison to a control group of 379 prospective mothers, age 20 to 30, there were five stillbirths in the mature age group and none in the younger age group….After a woman’s mid 20s there is a decline in fertility, with dramatic changes during a woman’s 30s and 40s….
“Even a cursory glance at the information provided above would be disturbing for young people considering any delay in childbearing. It is not our purpose to scare people into earlier childbearing with this information, but rather to help individuals make informed decisions. More disturbing to us is that among the many reasons why women and men may avoid facing these facts is the possibility that the choice of children at a younger age is inconsistent with the current structure of careers. To the extent this argument is true, both public and private policies require rethinking and restructuring.”
So bottom line, here is an issue we can do something about. Policy could make an impact. Wolfgang Lutz has suggested that we try informing women of the risks involved in postponement, and also make changes in our education system to enable flexibility between being a mom, and say, postgraduate study, or other kinds of career enhancing activities which could be easily combined with the early months and years of parenthood. Housing policy would be another area which could be scrutinised. The interesting thing is that these are pro-natal measures which may be effective, but which are not intrusive, since they help people do something they want to do, and don’t try to push them into doing something they otherwise wouldn’t do.
So, finally, what is the point about menarchÃ©. Well Brad’s post is about a paper from David Weil, “Accounting for the Effect of Health on Economic Growth“. As the post Brad links to explains “According to David Weil, in South Korea, the average age (of menarchÃ©) dropped from 16.8 to 12.7 between 1958 and 1998.” On David Weil’s account healthy eating leads to increased biological fertility (or fecundity), and in this way diet and living standards form part of our reproductive history.
As I point out to Brad in the comments section this work on health and reproduction also shows up some of the cruder applications of Malthusianism among economists. The positive checks have a biological element connected with female reproduction – or should these be nature’s preventive checks. Whichever way you look at it there is a positive feedback/negative feedback process as better diet improves fertility (or fecundity in the biological sense) and this may also then be associated with better economic prospects encouraging an increased rate of new home/family formation at a younger age. (Think UK pre industrial revolution from end 16th century). Also being more fertile, the gap between the birth of each child will be reduced. During the Malthusian, or pre-demographic transition, regime the whole thing kicks down again as the population grows beyond a critical point . In reality I doubt the menarchÃ© age is so important here, as most societies have pretty systematic rules governing marriage and family formation. But where it really does get interesting is in the case of Korea, since this blog post about a substantial drop in age of first menstruation is accompanied by news that S Korea is just about to start an active pro-natal campaign to try and offset the drop in the birth rate. Now the interesting question would be, is there any connection? I really am not qualified to reach a conclusion, but given everything I have outlined in the earlier part of the post, the correlation does just jump out of the page: the drop in menarchÃ© age means the age-fertility bell curve moving to the left, while the age at childbirth distribution curve moves to the right. There is a mis-match here somewhere.