3 ms·

Your source says “the fatality rate did not change appreciably”.

lxgr 2y ago
Injuries did increase, though, and I can't think of a plausible mechanism that would somehow cap expected outcomes at "injury but not death".
- d1sxeyes 2y ago
  So we were talking about excess deaths, which means that supporting your argument with a paper that argues that a previous finding of excessive deaths was flawed is probably not the strongest argument you could make. Increased number of injuries but not deaths could be, for example, (purely making things up off the top of my head here) due to higher levels of distractedness among average drivers due to fear of terrorism, which results in more low-speed, surface-street collisions, while there’s no change in high speed collisions because a short spell of distractedness on the highway is less likely to result in an accident.
  - lmm 2y ago
    > which results in more low-speed, surface-street collisions, while there’s no change in high speed collisions because a short spell of distractedness on the highway is less likely to result in an accident. That's not a remotely plausible model though. There are recorded cases of e.g. 1.6 seconds of distractedness at high speed causing a fatal collision. Anything that increases road injuries is almost certainly also increasing deaths in something close to proportion, but a given study size obviously has a lot more power to detect injuries than deaths.
    - d1sxeyes 2y ago
      Yeah, I was not really trying to argue that that was actually the case, so won’t waste time trying to defend the merits of the model I pulled out of my arse. Alternatively then, perhaps safety developments in cars made them safer to drive around the same time? Or maybe advances in medicine made fatal crashes less likely? Or perhaps there’s some other explanation that doesn’t immediately spring to mind, it’s irrelevant. The only point I’m really making is that the data OP referred to does not show an increase in excess deaths, and in fact specifically fails to find this.
      - lmm 2y ago
        > The only point I’m really making is that the data OP referred to does not show an increase in excess deaths, and in fact specifically fails to find this. That data absolutely does show an increase in deaths, it's right there in the table. It fails to find a statistically significant increase in deaths. The most plausible explanation for that is that the study is underpowered because of the sample size, not that some mystical effect increased injuries without increasing deaths.
        d1sxeyes 2y ago
        > That data absolutely does show an increase in deaths Please be careful about removing the word 'excess' here. The word 'excess' is important, as it implies statistical significance (and is commonly understood to mean that - https://en.wikipedia.org/wiki/Excess_mortality https://en.wikipedia.org/wiki/Excess_mortality). I didn't argue that there was no change in the number of deaths, and I did not say that the table does not show any change in the number of deaths. If your contention is that the sample size is too small, we can actually look at the full population data: https://en.wikipedia.org/wiki/Motor_vehicle_fatality_rate_in_U.S._by_year https://en.wikipedia.org/wiki/Motor_vehicle_fatality_rate_in... Notably, although 2002 had a higher number of fatalities, the number of miles traveled by road also increases. However, it represents a continuation of a growing trend since 1980 which continued until 2007, rather than being an exceptional increase in distance travelled. Also, while 2002 was the worst year since 1990 for total fatalities, 2005 was worse. Fatalities per 100 000 population in 2002 was 14.93, which was around a 1% worsening from the previous year. But 2002 does not really stand out, similar worsenings happened in 1988, 1993, 1994, 1995, 2005, 2012, 2015, and 2016 (to varying degrees). One other observation is that in 2000, there was a population increase of 10 million (from 272 million to 282 million), while other years on either side are pretty consistently around 3 million. I'm not sure why this is the case, but if there's a change in the denominator in the previous year, this is also interesting if we're making a comparison (e.g. maybe the birth rate was much higher due to parents wanting 'millenial babies', none of whom are driving and so less likely to be killed in a crash, again, just a random thought, not a real argument from my side that I would try to defend). The reason 'statistical significance' is important is because it allows us to look at it and say 'is there a specific reason for this, or is this within the bounds of what we would expect to see given normal variation?'. The data don't support a conclusion that there's anything special about 2001/2 that caused the variation.

lxgr 2y ago

Injuries did increase, though, and I can't think of a plausible mechanism that would somehow cap expected outcomes at "injury but not death".

d1sxeyes 2y ago
So we were talking about excess deaths, which means that supporting your argument with a paper that argues that a previous finding of excessive deaths was flawed is probably not the strongest argument you could make. Increased number of injuries but not deaths could be, for example, (purely making things up off the top of my head here) due to higher levels of distractedness among average drivers due to fear of terrorism, which results in more low-speed, surface-street collisions, while there’s no change in high speed collisions because a short spell of distractedness on the highway is less likely to result in an accident.
- lmm 2y ago
  > which results in more low-speed, surface-street collisions, while there’s no change in high speed collisions because a short spell of distractedness on the highway is less likely to result in an accident. That's not a remotely plausible model though. There are recorded cases of e.g. 1.6 seconds of distractedness at high speed causing a fatal collision. Anything that increases road injuries is almost certainly also increasing deaths in something close to proportion, but a given study size obviously has a lot more power to detect injuries than deaths.
  - d1sxeyes 2y ago
    Yeah, I was not really trying to argue that that was actually the case, so won’t waste time trying to defend the merits of the model I pulled out of my arse. Alternatively then, perhaps safety developments in cars made them safer to drive around the same time? Or maybe advances in medicine made fatal crashes less likely? Or perhaps there’s some other explanation that doesn’t immediately spring to mind, it’s irrelevant. The only point I’m really making is that the data OP referred to does not show an increase in excess deaths, and in fact specifically fails to find this.
    - lmm 2y ago
      > The only point I’m really making is that the data OP referred to does not show an increase in excess deaths, and in fact specifically fails to find this. That data absolutely does show an increase in deaths, it's right there in the table. It fails to find a statistically significant increase in deaths. The most plausible explanation for that is that the study is underpowered because of the sample size, not that some mystical effect increased injuries without increasing deaths.
      - d1sxeyes 2y ago
        > That data absolutely does show an increase in deaths Please be careful about removing the word 'excess' here. The word 'excess' is important, as it implies statistical significance (and is commonly understood to mean that - https://en.wikipedia.org/wiki/Excess_mortality https://en.wikipedia.org/wiki/Excess_mortality). I didn't argue that there was no change in the number of deaths, and I did not say that the table does not show any change in the number of deaths. If your contention is that the sample size is too small, we can actually look at the full population data: https://en.wikipedia.org/wiki/Motor_vehicle_fatality_rate_in_U.S._by_year https://en.wikipedia.org/wiki/Motor_vehicle_fatality_rate_in... Notably, although 2002 had a higher number of fatalities, the number of miles traveled by road also increases. However, it represents a continuation of a growing trend since 1980 which continued until 2007, rather than being an exceptional increase in distance travelled. Also, while 2002 was the worst year since 1990 for total fatalities, 2005 was worse. Fatalities per 100 000 population in 2002 was 14.93, which was around a 1% worsening from the previous year. But 2002 does not really stand out, similar worsenings happened in 1988, 1993, 1994, 1995, 2005, 2012, 2015, and 2016 (to varying degrees). One other observation is that in 2000, there was a population increase of 10 million (from 272 million to 282 million), while other years on either side are pretty consistently around 3 million. I'm not sure why this is the case, but if there's a change in the denominator in the previous year, this is also interesting if we're making a comparison (e.g. maybe the birth rate was much higher due to parents wanting 'millenial babies', none of whom are driving and so less likely to be killed in a crash, again, just a random thought, not a real argument from my side that I would try to defend). The reason 'statistical significance' is important is because it allows us to look at it and say 'is there a specific reason for this, or is this within the bounds of what we would expect to see given normal variation?'. The data don't support a conclusion that there's anything special about 2001/2 that caused the variation.