"Because of this legislation," New York Mayor Michael Bloomberg says of his about-to-be-enacted smoking ban, "it's literally true that something like a thousand people will not die each year who would have died." Presumably, Bloomberg is talking about people exposed to secondhand smoke. Since the evidence that secondhand smoke kills anyone–let alone New York City bartenders and waiters specifically–is highly debatable, you may wonder how he arrived at this number.
First, Bloomberg must have ignored all of the problems with the epidemiological research, typically involving wives of smokers, that links secondhand smoke to lung cancer and heart disease. Second, he must have estimated how the exposure of a restaurant or bar employee compares to that of a woman married to a smoker. Third, he must have translated that exposure estimate into a year-by-year risk estimate. Fourth, he must have known how many employees now work in smoky environments, and how long they would have continued in the same jobs. Then he must have estimated how many deaths could have been expected in this group without a smoking ban.
Or, just possibly, the mayor pulled the number out of thin air. Which seems more likely?