>How about increased taxpayer funded healthcare costs?

A known cost of socialized medicine.

Unless you want to go down the road of justifying any government coercion or loss of freedom as a taxpayer cost saving measure.

My point was that

> but requiring taxes to cover the negative externalities from vice is fine, e.g. funding DUI checkpoints).

Is not as simple as it may sound.

Subtract it from the lower social security costs

To be consistent, I would then also want to get into opting out of end of life healthcare which is where a huge, if not majority, of healthcare spend is.

Social security is not paid by other taxes. It's its own fund.

I do not find that clerical accounts for government expenses matter for practical purposes. Nominally, they can have various funding sources, but a politically popular expense will get its funding from somewhere, somehow.

It seems prudent to just treat all monies paid to the federal government as taxes, and all services/products received from the federal government as a whole when accounting for it as an individual taxpayer.

keeping very sick people alive if way more expensive than keeping older people alive.

Except tobacco use does not increase healthcare costs and in fact reduces them, due to people dying earlier and more quickly.

Perhaps for the age 65+ risk pool under Medicare (mostly taxpayer funded healthcare), but probably not for the under age 65 risk pools. Or at least I am not aware of tobacco causing significant mortality before age 65.

Overall. This is not hard to verify with some googling -- I posted some links in another comment:

https://news.ycombinator.com/item?id=29005498

Edit: deleted. Misunderstood authors point.

I don't think this is quite the argument you make it out to be, as we already have higher insurance premiums for smokers. Likewise, high-risk people are ineligible for organ transplants.

Really, anything can be a slippery slope if we want to look at it through that lens, but it's often not appropriate. This is one of those cases.

> people who take a car when they could take a bus, anyone who makes an unnecessary journey to do something that they benefit from such as church,

Some states sort of do this by requiring purchase of personal injury protection (PIP) from the auto insurer.