That’s true, but the probability mass function for total sibship size we estimate here would left-shifted if the non-survivors are absent. The reported family sizes would be smaller in kind.
I might be wrong that this would neutralize the effect you’re pointing out, but I think it does.
If we assume that the likelihood of a pregnancy leading to a child who lives long enough to be in our records is independent of the child’s order / mother’s age, then I agree that that the effects on the average birth order and average family size of our cardinals should in some sense cancel. However, it should still increase the error bars on both numbers and therefor the uncertainty of any conclusion. And I’m not sure I’d expect survival to be independent of order.
That’s true, but the probability mass function for total sibship size we estimate here would left-shifted if the non-survivors are absent. The reported family sizes would be smaller in kind.
I might be wrong that this would neutralize the effect you’re pointing out, but I think it does.
If we assume that the likelihood of a pregnancy leading to a child who lives long enough to be in our records is independent of the child’s order / mother’s age, then I agree that that the effects on the average birth order and average family size of our cardinals should in some sense cancel. However, it should still increase the error bars on both numbers and therefor the uncertainty of any conclusion. And I’m not sure I’d expect survival to be independent of order.