Isn't the RC church like the Mafia, once you are on the books, you never leave?
Same, I have heard, with the LDS and Episcopal.
Actually, those numbers are based on head counts of registered families in the parishes. And many, if not most, purge their records from time to time, based on whose contributing and who's known to attend. This has to do with things like baptisms and first communions.
I bet something like this is true for all groups who are claimed once in, always in.
Actually, the Catholic church does quite a lot to maintain an accurate, annual census.
Your perception isn't baseless: In many polls, people reply that they are Catholic even when they have left the Catholic church, as if to validate their position: "I'm a Catholic, and I think gays should get married; I'm a Catholic, and I think the schools should hand out condoms in the second grade," yadda yadda yadda... Then when they get asked how frequently they go to church, they tell the pollster how much they hate the Catholic church. So they don't go to church, they don't agree with any of the church's most basic teachings, they consider organized religion to be inherently corrupt, and they proudly worship pagan gods, but they tell pollsters that they are Catholic?
Further, there can be confusion as regards to baptism and Catholics in nations with established churches. Once baptized, a person remains forever a part of the church, according to Catholic faith. But that neither means that their salvation is assured, or they are considered Catholic: Baptism removes the stain of original sin, but can increase the judgment of committed sin. And nearly all Christians' rites of baptism are considered valid, so that hardly means they are members of the CATHOLIC Church (tm).
Finally, in many nations, C+P>T, or Catholics + Protestant > Total citizens. I believe... and may totally be wrong... that the reason why the number of Catholics remains higher in several largely apostate nations is that, having formerly had established religions, people continue registering with the Catholic church as they register with the state. I know the registration is not one and the same, but they can be very synchronized.
In Latin American countries, where there are very few priests per capita, there are probably very different registration rules; they'd be lucky to see a priest come to town once a year, let alone register each year! And I have heard that it is quite common for people to register with whoevere comes to town, accumulating several registrations in several sects.
I have a Philippino friend who is fairly ecumenical. She breaks me up. She remains the most devout of Catholics, but she'll never turn down the opportunity to reply affirmatively any time a friend invites her to go to a Protestant preacher. She believes, as the Catholic church teaches, in constant renewal of baptism, so she always goes along with any calls to be be baptized in the spirit, and would never pass up the chance to express her immense love for each member of the trinity, or to be prayed over.
So she'll enthusiastically sign up for any literature (probably inadvertantly registering at the same time); she'll respond to every altar call. The poor girl has probably become a member of 300 denominations just since I've known her!... But she is an everlast Catholic...
Not usually. If they don't know you, and you never put an envelope in the collection plate, and you don't have a child in the parish school, they usually try to purge you from the parish registry after 3-4 years.
People typically don't bother to notify the parish office when they (physically) move away, anyway, and there's no central database of parish registrations, so they have to do something like that.
No, that's not correct for us Catholics. It is - from my admitted limited understanding - the case with LDS, the Witnesses and other "new" churches.