The danger of overreaction

The California-based blogger Kevin Drum has a good post up today with the title Why don’t we do more prescribed burning? An explainer. There’s a lot of great detail in the post, but the bit that really jumped out at me was the history of the enormous forest fires that burned in Yellowstone National Park in 1988.

In 1988 the US Park Service allowed several lightning fires to burn in Yellowstone, eventually causing a conflagration that consumed over a million acres. Public fury was intense. In a post-mortem after the fire:

The team reaffirmed the fundamental importance of fire’s natural role but recommended that fire management plans be strengthened…. Until new fire management plans were prepared, the Secretaries suspended all prescribed natural fire programs in parks and wilderness areas.

This, in turn, made me think about the U.S. government’s effort to vaccinate the population against a potential swine flu epidemic in 1976, under the Gerald Ford administration.

The vaccination effort did not go well, as recounted by the historian George Dehner in the journal article WHO Knows Best? National and International Responses to Pandemic Threats and the “Lessons” of 1976

The Swine Flu Program was marred by a series of logistical problems ranging from the production of the wrong vaccine strain to a confrontation over liability protection to a temporal connection of the vaccine and a cluster of deaths among an elderly population in Pittsburgh. The most damning charge against the vaccination program was that the shots were correlated with an increase in the number of patients diagnosed with an obscure neurological disease known as Guillain–Barré syndrome. The program was halted when the statistical increase was detected, but ultimately the New York Times labeled the program a “fiasco” because the feared pandemic never appeared.

Fortunately, swine flu didn’t become an epidemic, but it’s easy to imagine an alternative history where the epidemic materialized. In that scenario, the U.S. population would have suffered because the vaccination program was stopped. I don’t know how this experience shaped the minds of policymakers at the U.S. Centers for Disease Control (CDC), but I can certainly imagine the memories of the swine flu “fiasco” influencing of the calculus of how early to start pushing for a vaccine. After all, look what happened when we tried to head off a potential pandemic last time?

When a high-severity incident happens, its associated risks becomes salient: the incident looms large in our mind, and the fact that it just happened leads us to believe that the risk of a similar incident is very high. Suddenly, folks who normally extol the virtues of being data-driven are all too comfortable extrapolating from a single data point. But this tendency to fixate on a particular risk is dangerous, for the following two reasons:

1. We continually face a multitude of risks, not just a single one.
2. Risks trade off of each other.

We don’t deal in an individual risk but with a vast and ever-growing menu of risks. At best, when we focus on only risk, we pay the opportunity cost of neglecting the other ones. Attention is a precious resource, and focusing our attention on one particular risk means, necessarily, that we will neglect other risks.

But it’s even worse than that. In our effort to drive down a risk that just manifested as an incident, we end up increasing risk of a future incident. Fire suppression is a clear example of how an action taken to reduce risk can increase increase risk.

As Richard Cook noted, all practitioner actions are gambles. We don’t get to choose between “more safe” and “less safe”. The decisions we make always carry risk because of the uncertainties: we just can’t predict the future well enough to understand how our actions will reshape the risks. Remember that the next time people rush to address the risks exposed by the last major incident. Because the fact that an incident just happened does not improve your ability to predict the future, no matter how severe that incident was. All of those other risks are still out there, waiting to manifest as different incidents altogether. Your actions might even end up making those future incidents worse.