There's a dynamic aspect to this that's difficult to capture in terms of straight up mortality risk.
For starters, we're more interested in the marginal average reduction of mortality per dollar invested rather than point in time risk. Like, the risk of flying on airplanes is fairly low relative to driving. But that's, in part, because we've already invested a huge amount into making air travel safe. It might not make sense to funnel future dollars into making air travel safe as opposed to cars. But if we were to lower that investment going forward, mortality would presumably go up. Because people aren't that irrational: Zooming through the air a mile in the sky, absent safety precautions, really is inherently less safe than driving on the ground.
That's extra true for something like security, where you're dealing with responsive opponents. The odds of a plane blowing up in a terrorist attack are low, but if the bad guys had a 100% successful method for blowing up a plane, they'd probably take it and the odds would go up.
Plus the odds also vary quite a bit based on the denominator too. For instance, the odds of death by flying are lower over the last X years. But if you were looking only at mortality risk from flying on the 737 Max in 2019, maybe that's different.
And then there's the non-mortality cost. Eating healthier food would reduce mortality quite a bit. But people like eating unhealthy things -- at some point, the extra life gained isn't worth it.
None of this is to say that the current degree of security theatre is worth it. Only that relative mortality is probably insufficient a measure.
For starters, we're more interested in the marginal average reduction of mortality per dollar invested rather than point in time risk. Like, the risk of flying on airplanes is fairly low relative to driving. But that's, in part, because we've already invested a huge amount into making air travel safe. It might not make sense to funnel future dollars into making air travel safe as opposed to cars. But if we were to lower that investment going forward, mortality would presumably go up. Because people aren't that irrational: Zooming through the air a mile in the sky, absent safety precautions, really is inherently less safe than driving on the ground.
That's extra true for something like security, where you're dealing with responsive opponents. The odds of a plane blowing up in a terrorist attack are low, but if the bad guys had a 100% successful method for blowing up a plane, they'd probably take it and the odds would go up.
Plus the odds also vary quite a bit based on the denominator too. For instance, the odds of death by flying are lower over the last X years. But if you were looking only at mortality risk from flying on the 737 Max in 2019, maybe that's different.
And then there's the non-mortality cost. Eating healthier food would reduce mortality quite a bit. But people like eating unhealthy things -- at some point, the extra life gained isn't worth it.
None of this is to say that the current degree of security theatre is worth it. Only that relative mortality is probably insufficient a measure.