One year ago a local government initiated an antismoking advertising campaign in local newspapers, which it financed by imposing a tax on cigarettes of 20 cents per pack. One year later, the number of people in the locality who smoke cigarettes had declined by 3 percent. Clearly, what was said in the advertisements had an effect, although a small one, on the number of people in the locality who smoke cigarettes.
The statement 'Residents of the locality have not increased their use of other tobacco products such as snuff and chewing tobacco since the campaign went into effect' most helps to strengthen the argument.