Sure, lower demand does indeed reduce smoking, and a reduction in smoking might decrease cancer (iirc that's really hard to prove as an isolated variable given that those who give up smoking tend to make other lifestyle improvements that could also account for the difference).

My point is that the solution is such a blunt tool. Given that smoking rates aren't relatively high in Iowa, smoking alone cannot be the major contributor to their relatively increased cancer rates. Were they to smoke more than any other state and also have high rates, I could maybe see it, but that's just not the case.

Even if smoking rates were high and and increasing the tax were a solution, I'd still suggest that it's rather lazy to only do that given that tobacco does not cause a majority of cancer.

You could do the same thing in a different direction and be equally relatively ineffective by, for instance, decreasing tax on sunscreen, or subsidizing healthy foods or gym memberships.

Given that stress contributes to cancer rates, you could decrease the cost of mental health, run a de-stigmatizing campaign, force all corporations to finance therapy with independently verified therapists etc.

There are so many many things that can be done that would likely be better than attempting to decrease an already low smoking rate.

>a reduction in smoking might decrease cancer

I understand that you were trying to make a different point so forgive me for derailing this conversation but this is important and I want to be emphatic.

Smoking incontrovertibly and substantially increases your risk of developing cancer. 85-90% of lung cancer cases and a substantial number of other forms cancers of can be attributed to smoking. There are a lot of ways to study this (you can look at people that never started smoking, not just people who quit). Yes, these studies are correlational (we don’t do RTCs on things that can kill you) but they are very high powered and are designed to account for confounding variables. The entire reason we’ve seen a decline in cancer mortality in the US since the 90s is largely attributable to falling smoking rates beginning in the 70s. And while much fewer people smoke, roughly 1 in 7 still do. Encouraging them to find another way to feed their nicotine addiction, and discouraging young people from ever picking up the habit, would save a lot of lives still.