One more thing is that evidently castration had a low survival rate. That makes long life conditional not only on having been castrated, but on on having been castrated and surviving it.
If there were such a mortality bias where the procedure kills the weaker, then unless native Egyptian surgical skills in the late 1800s are much better than Chinese surgical skills, I would again expect that to produce excess longevity in Egyptian eunuchs and not the Chinese/Korean eunuchs (which is the opposite of what we seem to observe).
That was a general point about eunuch longevity studies, not specifically about the Egyptian ones. I expect the techniques in Egypt and China to have beeen similar.
I expect that the survival rate should be incredibly close to 100%, if one goes to a surgeon rather than cutting himself. The number of years of life one should expect to lose from dying during an orchiectomy times the probability of death occurring then is going to be hundreds of times less then the expected number of years even a 30-year old would gain from castration.
The survival rate is close to 100% now. However the data that you rely on comes from previous centuries when the survival rate was low. Thus your data set has a literal survival bias.
One more thing is that evidently castration had a low survival rate. That makes long life conditional not only on having been castrated, but on on having been castrated and surviving it.
If there were such a mortality bias where the procedure kills the weaker, then unless native Egyptian surgical skills in the late 1800s are much better than Chinese surgical skills, I would again expect that to produce excess longevity in Egyptian eunuchs and not the Chinese/Korean eunuchs (which is the opposite of what we seem to observe).
That was a general point about eunuch longevity studies, not specifically about the Egyptian ones. I expect the techniques in Egypt and China to have beeen similar.
I expect that the survival rate should be incredibly close to 100%, if one goes to a surgeon rather than cutting himself. The number of years of life one should expect to lose from dying during an orchiectomy times the probability of death occurring then is going to be hundreds of times less then the expected number of years even a 30-year old would gain from castration.
The survival rate is close to 100% now. However the data that you rely on comes from previous centuries when the survival rate was low. Thus your data set has a literal survival bias.