3 ms·

Someone can be an only son regardless of the number of sisters he has

• yesenadam 8y ago
  >Someone can be an only son regardless of the number of sisters he has Yes, that's what my point was - "he could have had any number of sisters" - if you have 12 sisters, it's extremely unlikely you are an only son. The more sisters, the more unlikely being an only son is.
  • eruci 8y ago
    Yep, but the whole trick is finding a model that estimates the percentage of the male population that are 'only sons' at 0,1, and 2nd generation level.