Europeans may soon wish they lived in New York City.

A European Parliament committee voted on July 10 to ban flavored and slim cigarettes and cover three-quarters of each pack with scary pictures. Even if the legislation is somewhat softened in the weeks or months to come, Europe is clearly in for another round of screw-tightening that could make its anti-tobacco rules much tougher than anything in the U.S.

The current effort targets tobacco marketing. Slim cigarettes are sold as fashion accessories, which makes them potentially attractive to young women. Menthol is also a marketing ploy: It masks the tobacco taste, making it easier to start smoking. And cautionary pictures of cancerous lungs and ulcers will soon take up so much space on the pack that they will prevent tobacco companies from employing an attractive design, one of the last marketing tools still available to them.

Yet it is far from certain that attacking marketing techniques will have any effect on smoking. Although smoking rates have dropped dramatically throughout the developed world since 1990, there are no conclusive studies showing exactly which anti-tobacco measures have caused the decline. (The flavor ban, it seems, isn't going to dissuade former German Chancellor Helmut Schmidt, who has hoarded 38,000 menthols.)

In an oft-quoted 2004 article, researcher David Levy and co-authors noted that "most U.S. studies examine the impact of overall cigarette advertising expenditures on total cigarette sales, and obtain mixed results. The effects are generally not statistically significant or indicate a small effect on smoking. These conclusions also apply to studies from other countries." The situation has not changed much in the last nine years: The influence of advertising and marketing controls on smoking is much harder to measure than the effectiveness of advertising itself.

Another prevalent approach, making tobacco prohibitively expensive through taxation, is no less problematic. A 1999 World Bank study determined that a 10 percent increase in the price of cigarettes leads to a 4 percent decrease in consumption. If that were true, there should be no smokers left in the U.K., where tax measures have helped boost the price of a pack of cigarettes more than fivefold since 1991. Smoking prevalence in the U.K. is just 26 percent lower than in 1990.

What is missing is any type of concerted attempt to figure out which measures work and which do not. Well-designed studies would be needed to understand why Ireland, a pioneer of tobacco control, has seen only a 3 percent drop in smoking prevalence since 1990 -- the smallest decline among OECD countries. Researchers could also explore the relationship between the Nordic countries' excellent quitting record -- Sweden has seen a 46 percent smoking-rate decline since 1990 –- and the popularity of snus, a smoke-free product used like chewing tobacco.

About 19 percent of Swedish men use snus, which is banned in most EU countries. Studies have shown snus to be effective in helping people quit smoking, yet the new legislation in the European parliament could kill it off by banning the use of a key snus ingredient, baking soda. Without it, almost no nicotine is released when a user keeps a pinch of snus under the upper lip.

Smoking is deadly, yet fighting it pell-mell the way regulators do now is not particularly efficient. Tobacco companies have been smarter about adapting to the constantly changing rules than authorities have been about modifying them. Philip Morris' profits are higher now that they were three and four years ago. Regulators might even be doing the cigarette industry a favor by forcing it to cut marketing costs. After all, it is selling an addictive product. Some heroin dealers, too, attempt to brand their product. One has to wonder whether demand would drop significantly if they didn't.

(Leonid Bershidsky, an editor and novelist, is the Moscow correspondent for World View. Follow him on Twitter.)