Corporal punishment has been banned in the UK for at least 30 years (though when I was at school, they were allowed, it seems, to threaten with it but not actually do it...). Having worked in schools, I am not sure corporal punishment would actually make that much difference to behaviour or learning. It does not correct the bad behaviour, in some cases it reinforces it (especially when the motivation for bad behaviour is attention seeking, common in children) and a relationship based on fear is not a good one on which to build a trusting basis for learning.

I would also say that I am not all that sure behaviour is really not all that much worse than it was in the past. When a good teacher, one who has the respect of the class, walks into a classroom you can see the change in behaviour. This is not based on the promise of pain but rather on the respect and trust they have built with that class. Just as it is said that someone who swears has a poor vocabularly, I would say that someone who has to resort to physical punishment has a poor ability to relate to children.

Modern methods are nothing to do with child protection, risks of paedophillia or similar (these are separate issues...) but rather with understanding how learning is best achieved. The more you force someone to learn, the less inclined they are to actually want to do it. Instead you have to convince them that they want to do it for their own good. This is often a hard slog (I recently had to convince some girls whose dearest wish seemed to be limited to qualifying as hairdressers, despite some having the ability to do much more than that, that they did need science to learn hairdressing and that it was, in fact, central to the courses you have to do to be a hairdresser) but once you get that self motivation you have absolutely no problems in discipline or behaviour.