my anecdotal experience is the opposite. Lots of examples of alternate-generation smokers. Don't know what studies have shown in terms of actual data, though
Having a quick glance around here's one study relating to that: http://www.dbtechno.com/health/2009/02/05/children-more-likely-to-smoke-if-parents-light-up-cigarettes/
Here's the relevant extract:
[the study] found that children who were 12 or young when their parents were smoking were 3.6 times more likely to smoke later in life than kids who had parents who were non-smokers
It makes logical sense as well - if you're growing up in a house filled with smoke, you're going to suffer some second hand smoke, which just by itself would make you more likely to want to smoke I'd have thought, even before factoring in that you may look up to your parents and view it as more acceptable behaviour to smoke if they do.
I still think the example of loud music is a good one. It damages your hearing. It's legal. Should the gov be able to ban it for our own good? What's the difference?
Playing music so load that it damages the hearing of anyone nearby should be illegal in the case of an individual. Obviously it should be legal if for a business/venue where the sole purpose of that place is to play loud music, since people will come there for the music - a bit like people go to the pub to drink (which will harm them, but should still be legal). As for playing loud music that damages the hearing of people in a pub, I don't know of any pubs that allow their customers to do this (while pubs that provide such music are doing it as part of their 'services', which is a critical difference). I also wouldn't want to have my hearing damaged by a neighbours loud music - once the noise reaches excessive levels, there is a strong case for making it illegal since then it isn't just impacting on the person with the loud noise, but also on all their neighbours, and a line has to be drawn somewhere (it shouldn't be legal to make a constant noise so loud that you can't hear yourself think let alone speak if within 1 mile of the vicinity in a residential area, for example, and I don't think anyone could argue otherwise).
Who is going to enforce the ban?
Easy - at the most basic level you can have the punishment as a fine, allow anyone to report an offending pub/other public place, and then enforcement officers can respond, level the fine if needed, and cover the costs of the whole enforcement system. Assuming that the fine is enforced, that then means that the business owners look to prevent it to avoid receiving the fine.