This argument is some weak sauce. The Rube Goldberg chanin of events reasoning leaves a lot of gaps in cause and effect.

Which is a shame, because the basic arguments against the TSA are very strong. TSA searches violate the fourth amendment, and you could make an argument that they violate the third amendment as well. (If the government can't put soldiers in your home, they can't put uniformed officers hands in your pants either.)

Not to mention ineffective, misdirected and inefficient. So there's no need make an argument about indirect tangential effects.

(The people who won't take planes, maybe they're not driving cars. Maybe they're driving PIRATES!

So by this very stretched line of reasoning...

think of how many shark attacks have been prevented due to the rising cost of fuel! People can't afford to either drive or fly to a beach location. Hence, they stay at home in the Midwest. The probability of a shark attack has been greatly reduced. Therefore, increasing fuel costs = less shark attacks!

Really? Amy, I know you don't like the TSA, but this is a really weak argument at best.

*le sighs*

Simple statistical shifting of passengers from the safest form of long distance travel to a more dangerous form of long distance travel.

That's step one. Then they start taking into account such things as "...time trends, weather patterns, economic conditions, and unobserved highway conditions..." to quantify the things drivers and passengers encountered on the road that they would *not* have encountered had they flown instead of shying away from the impact the TSA has had on screening and boarding.

And note that, so far, they've crunched the numbers for when TSA came online. They've yet to do (or reach the point of publication) the following quarters/years so they've yet to hit the statistical pot holes and speed bumps that are when the TSA deployed their Advanced Imaging Scanner technology and the comprehensive pat-downs.

I expect Insurance Actuators will be reading this and the following studies with ... interest.

This argument is not at all weak. Discouraging air travel costs lives.

This reasoning is identical to the reasoning that the FAA used to come to a decision about whether to require parents of children under 2 years old to buy separate seats for child restraint systems. Buckling children under 2 years old on airplanes would on rare occasions prevent injuries and deaths from turbulence. But requiring parents to buy one more seat would increase the cost of flying and push so many families onto the road that nine children would die in car accidents for every air death prevented. That's why the FAA allows passengers to fly without purchasing seats for children under 2. Same reasoning. It was good enough for the FAA, but the TSA is impervious to facts.

I wonder how they would fare if measured measured in $ per water bottle confiscated...

There's no question that discouraging air travel costs lives. The same is true of discouraging rail travel. Well-intentioned regulations that (a)require very heavy construction for passenger rail cars, for safety in collisions, and (b)prohibit speeds in excess of 79 mph unless Automatic Train Stop equipment is installed certainly make passenger rail travel less attractive for cost and/or schedule reasons, and it's possible that the number of lives lost because people choose to drive instead exceeds the number of lives saved by reducing rail accidents and their effects.

Hmm. If the theory is true, there should have been a big uptick in motorist miles driven after 9/11 when air travel was shut down for a while. Looking at the DoT's FARS database, here's their miles-drive estimates (in billions of miles) for the years bracketing 9/11:

1997: 2.557
1998: 2.628
1999: 2.690
2000: 2.747
2001: 2.796
2002: 2.856
2003: 2.890

Here's the year-to-year deltas:

1998: 0.071
1999: 0.062
2000: 0.057
2001: 0.049
2002: 0.060
2003: 0.034

The trend is pretty steady through 2005; it slows down in 2006, and then reverses (the numbers start declining) when the recession hits in 2008. Over this same period, fatalities per miles drive declines steadily.

So I'm not sure I see the theorized effect. Of course, the TSA has gotten more onerous over the past five years or so. If there is an effect, it's hard to see due to the recession. (It's well established that miles driven per year are strongly correlated to general economic conditions.) Meanwhile, fatalities per mile driven continue to decline. However, airline fatalities are also declining; there has not been an airline accident with passenger fatalities (outside of third-tier operators in Alaska) in the U.S. since the Colgan Air Buffalo accident three years ago.

@Cousin Dave,

It's true that many factors impact overall travel miles and choices of mode of travel. A full accounting requires much more data, an elaborate regression model, and some statistical assumptions. However, if you believe anecdotally that the TSA's poor treatment of travelers, particularly in the last year since the sexual assault patdowns started, has convinced a million people to drive instead of flying, then it's predicted that 15 of them died in car accidents. There are 700 million or so passengers per year, so a million would be a tiny change of 0.15%. Surely with all the fuss we've heard, about a tenth of a percent of people changed their plans over it. Blalock and colleagues get a number something like 6% diversion to roads in the months immediately following 9/11 (though there could have been non-TSA reasons for this shift), which means more people died on the roads as a result of 9/11 than died on planes as a result of 9/11.

I can tell you that TSA's abusive procedures convinced me to switch six of my long-distance trips this year to driving. I am absolutely sure that TSA endangers my life with its worthless security theater, because I won't tolerate it.