Tuesday, May 5, 2009

Housing and Fertility

I mused that the credit crunch was killing the housing market, which in turn might be killing fertility; after all, does losing one's home really set the mood for love? First I took a look at new home sales, courtesy of the US census bureau. I normalized the housing sales by population to get something akin to a rate.
Wow, look at that housing market crash! Next I took a look at recent total fertility rate, cobbled together from two sources. 2.1 is the magic replacement fertility level; apparently, we're experiencing a baby boomlet. However, in past recessions fertility rates dropped, so the boomlet might not last.
It's possible to regress the housing sales against the fertility rate and get a good p value if a two-year lag is used. It predicts a total fertility rate of 2.04 for 2010. Will this prediction hold up? My gut tells me the decision to have children is probably better related to unemployment numbers, and housing has been so bonkers this decade that using it to predict anything is questionable. However one of the fun things about blogging is the time capsule aspect, so I'll check back in 2011.

Another oddity I dug up while looking into this: multiple births have been steadily rising in this country for some time.

1 comment:

  1. I would guess that the rising multiple-births rate is due to improvements in and increased use of medical fertility treatments, from simple fertility drugs up through in-vitro fertilization.

    I found one paper whose abstract addressed this (over an earlier time period):

    Infertility treatment and multiple birth rates in Britain, 1938-94.

    http://www.ncbi.nlm.nih.gov/pubmed/9881133

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