20110906 corngrainelevator
Vern Panning, 70, strains while loosing a door to dump corn into an elevator October 31, 2005, at The Deshler Farmers Elevator Company's Custar elevator located in Custar, Ohio. - 

Jeremy Hobson: All this week, we're looking at how 9/11 has changed the landscape for American business, ten years on. And for companies large and small, spending on "security" continues to grow.

But as Marketplace's Jeff Horwich reports, some have questions about whether that money is well spent.

Jeff Horwich: Airlines: Sure. The Super Bowl: Naturally. Grain elevators: Say what?

For you city-folk, grain elevators are America's rural skyscrapers. Farmers dump their corn, wheat, soybeans. Trucks haul it out to feed the country. Even though elevators are mostly in the middle of nowhere, Bob Zelenka of the Minnesota Grain and Feed Association says you never know.

Bob Zelenka: It's on the edge of town, so could somebody step in here and adulterate some grain? I guess it might be easy enough to do. But those are the kind of things we've changed -- in terms of locking down, which we never used to do, being aware and vigilant.

9/11 meant new fences, lighting; training on what to do with suspicious requests for ammonium nitrate, a fertilizer that can be used make a bomb. Many grain elevators also store farm chemicals. Zelenka says elevators are now required to track every kernel -- where it came from, and where it's going.

Zelenka: It's been thousands of dollars that elevators have spent. You take that times 14,000 elevators nationwide, and that's a big chunk of dough.

Too much dough, if you ask John Mueller. He's a professor at Ohio State and co-author of the new book, "Terror, Security and Money."

John Mueller: Maybe we're much overreacting and overspending for a threat which is extremely limited.

Mueller estimates the U.S. private sector spends at minimum an extra $10 billion a year on security since 9/11. From grain elevators to shopping malls, he says rarely does the math make sense.

Mueller: We looked at the cost, for example, of protecting a large office building. The costs to retrofit a building to deal with say a truck bomb and so forth are not worth it unless the probability of the building being hit is 1,000 times higher than it actually is at present.

9/11 may have hit private businesses. But Mueller says nearly every foiled plot since then has had a government target -- mostly military. As for grain elevators: Mueller says not a single case has targeted the U.S. food supply. Of course, this all makes sense on paper.

But back at the elevator, Bob Zelenka says a different logic -- 10 years on -- continues to prevail.

Zelenka: You can't be too safe I guess, these days, unfortunately.

In Vermillion, Minn., I'm Jeff Horwich for Marketplace.

Follow Jeff Horwich at @jeffhorwich