Yeah, or it's also possible that your dozen kids would have a dozen kids each and all live on child benefits
Actually, it's not really like that in Canada. You don't get too much extra money for having kids. You just pay a bit less in taxes. You still have to make the money to pay (or not pay) taxes off. I think the European system is nicer. The single people can afford to pay a bit more in taxes, they still have a lot left over. The people with kids need it more.