Do “sin taxes” work?

"The government" is people. Are you arguing that society, collectively, should not establish a system of rules that reflects their social norms?

That's a different story. Externalities should be taxed to the extent of the cost of the externality to society (if not outright banned, which is not practical for most common externalities like running a combustion engine, breathing, etc.).

But pure sin taxes like soda/gambling/recreational drug taxes, where an individual is only affecting themselves, are effectively the government and busybody supporters of the policy playing god of morality. I've actually heard people suggest that drinking soda or using pot is an indirect externality as a result of the potential to 'change' users, and that its indirect effect on society via people's free association with such things is a justifiable externality. That implies that society is entitled to aspects of a person actions and characteristics outside of their lawfulness. It's a very socialist and anti-individualist argument, which I disagree with on a fundamental level.

Now for cigarettes, on the other hand, there are two potential externalities to tax. 1. The smoke that affects anyone near the user. 2. The addictive factor (nicotines), which is an externality against its users created by (and the tax should be applied to) the manufacturer.

Not to mention all the environmental externalities that should be applied at each stage of the supply and manufacturing chain due to fuel/processing/chemical effects on the environment/energy used/etc. However, these are common to all externalities, and if I had my way I would tax externalities in a direct and systematic way like this across the board, such that the tax is sufficient for the government to "undo" the externality. If there is no feasible way to undo it, it should be illegal.

Not saying you are totally wrong but the federal income tax has been already existing for decades at this time and the max and min rates actually went down during the prohibition era (per wikipedia). It only went up in 1932 a year before its repeal following the start of the Great depression. If it was a goal of the prohibitionists to hike up that tax it was largely unsuccessful.

>What if there was solid data decisively showing that there were substantial externalities effectively being paid for by the public?

That's always a risky argument to engage in. Everything has externalities, whether it's "sinful" or not. For example, there are a lot of externalities that the public pays for in order to allow everyone to drive a car. Probably round 30% of the driving public should not be driving a car. In western countries, drivers licence programs are much more about babying idiots through the basics of car driving than they are separating the incapable and denying them access. I don't know anyone who has wanted a drivers licence and been refused one. I do know multiple people in multiple countries who have taken the test more than 3 times to get it.

For the moment, we still value granting people freedom of movement. A society where there are two classes, those who can move themselves and those who cannot, would be deeply undesirable to most of us.

I for one value the right of people to make their own life decisions. The notion that my tax money might be used to treat lung cancer or buy sturdier surgery tables for obese patients doesn't bother me. What the hell is the point of a health care system if not to isolate ourselves from the harsh realities of life that prevent us from enjoying ourselves?

I don't want to live in a society where there are two classes, those who can pay for private health cover and therefore drink as much as they want, and those who cannot and thus may not party too hard. That might sound a bit weird, but would you want to live in a society where if you can't afford private health care you're not allowed to cycle on public roads?

I'm always in favor of letting people making their own decisions and then supporting them no matter the consequences. When that cost is spread across an entire society, it's a pretty light burden. Could be lighter if we stop letting companies dodge taxes tho.

The MPOWER WHO (World Health Organization) plan to help with tobacco cessation is comprised of 1. raising taxes, 2. banning smoking in public places, 3. scary anti-smoking ads of about $1 to $2 per capita per year and 4. doctors speaking to their patients about quitting, 5. patients using nicotine replacement therapies and 6. telephone counseling support.

This combination has been shown to be highly effective. Over 1/2 the contribution of getting people to quit or to never start comes from raising tobacco taxes.

Other studies show that by taxing sugar-sweetened beverages (SSBs) such as Coke by about 2 cents per oz. (in the US) shifts demand to healthier drinks such as water since most of these who consume SSBs are of limited financial means.

So, in fact when used in concert with overall formulas, the "sin taxes" are in fact effective.