Having said that, I think that effect explains only part of the 40%, but can't explain all of it.
No it wouldn't.
People make those excuses because it's weed, but you would have never posted that on an article about alcohol.
Well of course not, as the two drugs have completely different intoxication side effects.
Why did you automatically assume the point of bias?
A similar result about alcohol would be the (hypothetical) statement that the rate of drunk drivers in fatal accidents was constant before and after the enactment of Prohibition.
I do agree that the fact that fatal THC% stays constant before and after legalization is a surprise.
(Not that it really matters since I don't buy for a second that anywhere near 40% of people/people-driving are high at any given time. I also don't put much faith in numbers in the abstract of a a yet-to-be-published study...)
THC in the blood doesn’t mean actively high for habitual users, which would be most users if THC consumption is high. It means recent use, but not clear impairment.
And the study doesn't seem to differentiate between the different types of THC either, some of which are not psychoactive at all and which people use to relieve pain and anxiety. There's quite a lot of people using non-psychoactive THC which wouldn't impair driving.
It doesn't say anything about the distribution, only that the "average" (presumably, the arithmetic mean, a measure particularly sensitive to distortion by outliers) was at a particularly high level.
Can you explain what you mean by this?
If 40% of the whole population has THC in them, we'd need a control population (maybe from earlier when thc was less prominent) to see if per capita deaths has meaningfully increased. I'd do the same study, tangentially, for tech workers to see if productivity has changed when controlling for other variables.
That would be true if you looked at a variable which is not influenced by driving, like the percentage that wear red jumpers, but one would hope that not everyone is reckless enough to be highly intoxicated and drive.
This is again THC apologizism, nobody would even begin to suggest this if we were talking about alcohol.
When we talk about alcohol, we explicitly separate presence from impairment using blood alcohol concentration. We set legal thresholds because studies show a sharp increase in crash risk above those levels, relative to sober drivers. If alcohol were evaluated by merely asking "was alcohol present?" we would massively overestimate its causal role the same way THC is being overestimated here.
The problem with THC data is not that baseline comparisons are illegitimate; it's that we lack an agreed-upon, time-linked impairment metric comparable to BAC. THC metabolites persist long after intoxication, so presence alone is a weak proxy for risk.
So applying baseline controls to THC is not "apologism", it's applying the same evidentiary standards we already demand for alcohol, so the opposite of what you said.
This is literally how safe legal limits were derived.
If we are at 40% of the population being high at any given moment I think we are having extremely serious societal problems around mental health. Occasional use is not a big deal IMHO, but if a person is spending 40% of waking hours impaired that person has some serious unmet psychological needs.
I'm arguing that if the population data looks anything like the autopsy data, it would imply a massive epidemic of THC overuse.
Not really, due to THC content in the body not being a reliable indicator of impairment or even time since use.
If BAC were more like THC levels, I suspect the data would show 40% or more of the population has consumed alcohol - or, in your words, is drunk "at any given moment"