Are smokers less productive at work?

I used to work at a shop where approximately half of the employees were smokers and half were not. The smokers used to take extra breaks and longer breaks in order to get their fixes and it used to drive the rest of us crazy. Why should they get to work less because they smoke?

According to this article, that sort of thing might be a regular occurance. A study conducted by U.S. Navy showed that, on the job, smokers were generally less productive, took more sick leave and tended to have a higher instance of personality disorders. The study, which followed the careers of women in the Navy, also found that non-smokers often made more money than those who lit up daily.

The piece is quick to point out that so far there is no direct correlation between job performance and smoking, and a doctor from San Diego State University comments in the article that those who smoke might also have other personality traits, such as non-conformity and higher risk taking, that would lead to the results observed in the study.