These population registers therefore allow for a more competent census.
In Spain, it's pretty much the same thing as here, but I guess Spain still uses the traditional census despite having a national population register as well.
It's also easier for elections: with a CPR, you can easily screen for every voting-age and voting-eligible person in the country, who are then automatically registered to vote.
Yeah, this is all correct, I guess you are right
For the record, like you say Spain does do a more traditional census as well I think
However it is worth noting that Spain's apportionments get done by the CPR based off your registration, which update on a yearly basis. This is also why reapportionment here happens basically every time an election gets called. And like you say, it also allows for automatic voter registration at whichever adress you are registered on.
This does create some niche scenarios where people who move shortly before election day have a hard time figuring out where they have to vote but I guess it's a very small number of cases.
