This is the Cato Daily Podcast for Tuesday, January 6, 2009.

I'm Caleb Brown.

How do policy makers predict the likelihood of terrorist events?

How should they do so? Ben Friedman, research fellow in defense

and homeland security studies at the Cato Institute, believes that all too often estimates

come out of thin air. Policymakers too often choose alarmism over real risk assessment.

Friedman will be among the speakers at the Cato Institute's Counterterrorism Conference scheduled

for next week. You can register at Cato.org.

All over the media a few weeks ago was this report, a bipartisan commission report shared by

former senator James Talent and

former Senator Bob Graham on WMD weapons of mass destruction and it was

one of these blue ribbon commissions and they made a number of sensible recommendations in the report about dealing with nuclear and biological weapons proliferation.

But they also said, and this is what grabbed all the headlines, that it's 50% likely,

in other words more likely than not, that there'll be some kind of WMD attack in the

next five years perpetrated by terrorists somewhere in the world.

And what I found striking about that claim was there was no justification for it anywhere in that

100 page report.

In other words, what they said was that, well, we talked to a lot of experts and that's sort of where we came down our gut feeling, but there's no math, no quantitative justification for them to come up with that.

So I think they basically just decided to make an alarmist statement in order to generate headlines

and it worked.

And I think, you know, if you did really sit down and try to figure out how likely it is and you were fair and honest about it,

you come down with something far lower.

...