[Facts] Re: Best source for US given name popularities? ATTN: CKE
Sorry I didn't see this until today.
I believe that back when the SSA site did not have year-by-year lists before 1990, but only had decade by decade lists for the 1880s, 1890s, 1900s, 1910s, etc., that those lists were based on a 1% sample of all people who had birthdates listed in those decades. But I believe that when the SSA expanded its site to include lists for every individual year from 1880 on, that it created those lists from the full data set. I think that if they were still using just a 1% sample, there would have to be more ties in the numbers the report for the names on their year by year lists than there actually are. :)