According to new data, youths are smoking less.

From Morgan Stanley's David Adelman:

Although the causes are somewhat unclear, updated data from the National Survey on Drug Use and Health (NSDUH) highlights continued and substantial declines in the prevalence of US youth smoking. For example, among 12-17 year olds the incidence of cigarette smoking in the past month declined from 13.4% in 2000, to 8.4% in 2010, to 7.8% in 2011. In the 12-year data set, youth cigarette smoking has essentially declined every year, with most declines statistically significant (including 2011 vs. 2010).

Why has this been happening?

There are many reasons in our view why the secular rate of US cigarette volume decline has increased. We have written about this dynamic extensively, and the multiple – and somewhat related – principal factors likely include: (i) Reduced social acceptability; (ii) Increased prevalence of aggressive indoor smoking bans; (iii) Higher prices and higher excise taxes; (iv) Some shift to other tobacco products, including moist smokeless tobacco, as well as lower-taxed cigarette alternatives (e.g., “pipe-your-own”); (v) Ongoing ethnic shifts toward Asian- and Hispanic Americans, who have a far lower smoking prevalence (as well as substantially lower per capita cigarette consumption among those who smoke); and (vi) The multi-year substantial and continuing decline in youth smoking prevalence. Total youth consumption is modest, but like a python eating a pig, the impact of these demographic dynamics will be visible over an extended period of time as today’s young adult cohort ages. Nine-month year-to-date US cigarette consumption is down ~3%, despite only very modest net pricing.

Here's a chart showing that trend. But as Adelman notes, some may just be shifting from smoking to using smokeless tobacco products.