I finally found the data I was looking for. I believe it was so hard to find because it's so fundamental that it just isn't of interest, and therefore does not show up in Google searches (even a search of journals like PubMed probably wouldn't turn it up).
This article contains the following graph, showing how births dramatically decrease as a function of paternal age:
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If we take anyone vertical slice (such as the rightmost points) - it shows how births drop off dramatically with paternal age:
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note: this data includes
all births in a family, so the
start of families is probably even
more pronounced, since it will very strongly bias the data toward the left/younger.
So, I don't think anyone doubted this outcome.
Now we'll add some "advantage factor" - wealth or good looks. These could be anything, but I've made it a constant across the board - independent of age:
View attachment 234457The question now becomes
just how big an advantage must it be in order to more than offset the huge drop in changes due to increasing age?
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