NYTimes Op-Ed On Earthquake Safety in Seattle

2010 March 28
by Daniel Lakeland

Peter Yanev writes in the NY Times about how Seattle is subject to mega-earthquakes, and is not ready for them.

This is a topic close to my heart obviously. It is easy to say that all else equal, buildings that are safer in earthquakes are better. The problem is, all else is never equal. Safer buildings are expensive. Especially if you have to demolish a currently functioning building to put up a safer one. Even if you are only retrofitting the building, it is expensive.

And when I say that it’s expensive, you might be thinking that I’m talking about how much money it would cost, and you might be saying something like “money is a small price to pay for human lives” but I’m not talking about money. I’m talking about “real” economic expense. In Economics, all costs are opportunity costs. The cost of retrofitting or replacing a building is exactly equal to the next best thing that you gave up which you could have had if you hadn’t used those resources. So let’s examine some of the costs of retrofitting every building in Seattle to meet the requirements of a magnitude 9.2 earthquake on the Cascadia fault:

  1. Lives lost in construction worker accidents.
  2. Hours of peoples lives lost in sitting in traffic due to intense downtown construction.
  3. Materials used to retrofit buildings which could have been used to build new buildings.
  4. Hospital equipment not purchased with the money used for construction, and therefore not saving lives.
  5. Car accidents which could have been avoided with newer cars or better freeway construction.
  6. Lost productivity of buildings which could have been used to earn money to buy the things above.

When it comes to deciding on the “costs” of raising code requirements, too often Engineers consider only the dollar costs of the labor and materials. It turns out that in all likelihood those costs are negligible in the overall calculation, and yet they are the only ones we consider!

The case of downtown buildings as compared with something like Hurricane Katrina in New Orleans is completely different primarily because of the associated costs and benefits. This shows how these calculations should be done. First of all, heavy floods occur much more frequently than extreme earthquakes, so the probability that your engineering retrofit would be useful is higher, second of all, strengthening levees had essentially no associated costs of loss of materials (from demolishing a valuable building), loss of occupation and productivity is minimal, and traffic induced costs would have been localized to a region around the levees rather than a busy downtown business center. So considering the overall picture properly is important for evaluating change.

Where can we, as Engineers, make the most contributions today to safety? By improving the evaluation of safety tradeoffs, and inventing new, lower overall cost ways to improve safety. For example, if downtown buildings could be made safer by carefully base-isolating an existing building, column by column, without loss of occupation, that is a huge win for society by avoiding the loss of use costs and other similar costs.

Choosing to boost code requirements for new buildings is a natural way to improve through time without incurring the costs of loss of use of existing buildings. Also, working hard to produce economic well being for people is important. Wealthier people generally experience less overall costs from disasters. Making these tradeoffs is something that Economists and Engineers should be getting together to study.

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