Notice that age of first marriage of baby boomer females as given in http://aspe.hhs.gov/hsp/trends/change.pdf matches closely the peak cohort for 1980 as well as the peak in crude oil prices in constant (1996) dollars near 1980. Onset and drop-offs of these variables also match.
Also notice that mortgage rates, crucial for nesting and reproduction at first marriage, skyrocketed to a historic record high right when boomers, those "spoiled brats" produced by the GI generation, were trying to settle down and have children. Finally note the radically different way government policy affected the WW II GI generation seeking their first mortgages compared to the treatment of their children at the same phase of life. Who was "spoiled", really?
The variety of variables that can be predicted by positing female baby boomer fertility as the primary control variable appears potentially very wide-ranging.