I don’t expect there’s any good data on women under age 25. Your claim that 19 is the best age appears to be based on the one graph of “fecundability”, which is not the probability of pregnancy conditioned on trying but the probability of pregnancy conditioned on nothing, i.e. it’s confounded by whether the couples want kids. It’s from a paper that’s been unpublished for 3 years now.
You have some graphs based on Herasight’s model, but I don’t believe Herasight’s model is based on much data from young women. I’m happy to be corrected if wrong; do they have much data on women below age 25? They’re likely just extrapolating backwards from the data they have about older women.
I don’t expect there’s any good data on women under age 25. Your claim that 19 is the best age appears to be based on the one graph of “fecundability”, which is not the probability of pregnancy conditioned on trying but the probability of pregnancy conditioned on nothing, i.e. it’s confounded by whether the couples want kids. It’s from a paper that’s been unpublished for 3 years now.
You have some graphs based on Herasight’s model, but I don’t believe Herasight’s model is based on much data from young women. I’m happy to be corrected if wrong; do they have much data on women below age 25? They’re likely just extrapolating backwards from the data they have about older women.