Assuming the choice is never exercised, couples produce the same amount of children with the same gender distribution regardless of surname and these children are all just as likely to find a partner, in theory, the distribution of surnames should be in equilibrium. Of course ignoring name changes, migration and other things playing into the availability of surnames.
Following this logic, these 5% of couples using the maiden name of the bride are the ones actually leading to any kind of long term change. Which to me implies Sato can only be the surname of a majority if the majority wants it to happen.
Assuming the choice is never exercised, couples produce the same amount of children with the same gender distribution regardless of surname and these children are all just as likely to find a partner, in theory, the distribution of surnames should be in equilibrium. Of course ignoring name changes, migration and other things playing into the availability of surnames.
Following this logic, these 5% of couples using the maiden name of the bride are the ones actually leading to any kind of long term change. Which to me implies Sato can only be the surname of a majority if the majority wants it to happen.