Tuesday, September 18, 2007


I do research in public policy and have taught policy analysis to professional students in a variety of fields. Good policy research should acknowledge any tradeoffs between policy objectives, and discussions of risk usually involve tradeoffs between incremental increases in effort and incremental reductions in risk. It’s a rare case where risk can be eliminated completely. The cost of further reduction in risk usually gets far too high long before the risk gets to zero. Yet recent public discourse on the safety of highway bridges and the risks of domestic terrorist attacks have often explicitly or implicitly assumed otherwise.

On the right/conservative side far too many people are willing to surrender civil liberties without any explicit discussion of what marginal security benefit might be provided. The Bush Administration isn’t even willing to acknowledge how civil liberties are being curtailed or to identify what programs are being implemented. The Democrats in Congress, despite opposing the president’s wiretapping bill, passed it before taking summer recess (although they included a six-month sunset provision). Part of the reason for their passage seems to be a fear that they would be blamed if any terrorist attack of any kind happened in the interim. They say they will pass a bill with more limited authority this fall.

Almost everybody seemed to be in a frenzy over the Minneapolis bridge collapse, although concern about the budget limitations were raised by some on the right, including President Bush. Oddly, most of those same budget-conscious people were not especially concerned about budget limitations when the Republican Congress passed pork-laden highway bills (which included plenty of pork for Democratic as well as Republican districts). The infamous “bridge to nowhere” in Alaska costs almost as much as the estimated cost of rebuilding the collapsed Minneapolis bridge that carried over 100,000 cars per day. The cable news channels managed to round up some level-headed experts, including several university engineering faculty. The experts would say there was no reason for anybody to be nervous about driving over any bridges on their way to work, and then the reporters would panic like the bridge decks were papier-mache ready to dissolve in the next rain.

The September 11 terrorist attacks killed 2944 people and no domestic attacks have occurred since, although a number of plots have been interdicted. The bridge collapse killed 13 people and a similar collapse seems to happen every five or six years. Both are tragedies, but someone heading out the door to work faces other far greater risks of traumatic death every day. Some examples:

  • Total dead from motor vehicle accidents in the United States 2001-2006: 256,873 (117 per day).
  • Total dead from firearms in the United States 2001-2004 (the latest year on the Centers for Disease Control website): 118,974. This number includes suicides, homicides, and accidental deaths. Omitting suicides, the average is over 30 per day.
  • Total dead from homicide in the United States 2001-2005 (the latest year on the Bureau of Justice Statistics website): 81,679 (45 per day).

The terrorist attacks did require some policy changes. The bridge collapse is a reminder that we might not be spending enough on infrastructure maintenance, and bridges of similar construction are now being inspected more closely. But the figures above provide some obvious comparisons for alternative uses of resources. Would additional FBI attention and federal expenditures aimed at firearm enforcement and non-terrorist homicides reduce deaths better than additional money related to anti-terrorism measures? Would additional money spent on other highway safety measures, like median barriers that prevent crossover head-on collisions, reduce more deaths than investments in bridges? And what marginal change in security is earned by major compromises on constitutional protections concerning due process and government search and seizure?

Whenever I hear some threat to public health or safety going 24/7 on the news I just wait for someone to cite statistics like these to keep things in perspective. Most of the frenzies just seem to fade away after a while when the public attention moves on to another topic. The terrorism frenzy unfortunately still runs strong six years later.

I posted a poem about this topic on my other blog, Angles and Rhymes.