I have found records of the Axel family I am researching in several censuses. In addition, I have death records for both Peter and Sarah, the mother and father of the family. Below I present, in convenient tabular fashion, their ages as culled from the relevant census and death records:
Peter Sarah 1900 40 35 1900 Federal census 1905 50 42 1905 New York State census 1910 49 48 1910 Federal census 1915 60 54 1915 New York State census 1920 58 52 1920 Federal census 1922 70 Peter's death 1925 64 1925 New York State census 1930 69 1930 Federal census 1933 73 Sarah's death
While I cannot be certain of who reported these ages in many cases, the 1920 and 1922 dates are most likely due to Sarah: She signed Peter's death certificate, and she was the only person not working outside the home in their household in 1920. So how on earth could her husband have aged 12 years between those two events? And she herself regressed nicely between 1915 and 1920. Merlin would be proud of her!
Both of them were born in Russia and emigrated around 1890, so I don't have any primary sources for their dates of birth. Other than throwing up my hands, how should I interpret these numbers? Which year of birth is a good inference from all of this? Do I resort to plotting regression lines?