After the great San Francisco earthquake of 1906, the first massive efforts of earthquake engineering were undertaken in California with high expectations of economic return. Earthquakes would inevitably strike the region again, and reinforcement of new buildings would mitigate future losses. Consequently, building codes were established in 1933, resulting in today’s Uniform Building Code still evolving. Increasingly stringent requirements have led to higher and higher construction costs.
As a result, several important questions have arisen: What are the expected benefits of earthquake engineering as required by the Uniform Building Code?
Are present requirements adequate to make the seismic risk “acceptable”? If not, what would be the marginal return of more stringent codes? Other questions concern techniques for the prediction of earthquakes: identification, monitoring, and understanding of precursor signals.
On the one hand, there is skepticism about the success of the research in this field, fear of the loss and social disruption caused by false alerts, and uncertainty about the economic dislocation that a long-term, credible prediction could trigger. On the other hand, a successful prediction could save many lives, perhaps at a lower cost than that associated with more stringent building requirements.
Essay: San Francisco Earthquake
Given the present state of building practice and foreseeable improvements in prediction techniques, what are earthquake prediction’s probable costs and benefits?
Questions like these can be asked in many countries; the answers will vary widely since they depend on local seismicity and building techniques. The problem, in any case, is one of public decisions under uncertainty.
One could argue that the decision to reinforce a new building should be left to its owner if he will be solely responsible for the consequences of his choice.
But this is rarely the case, as many buildings are rented to others for residential, commercial, or industrial use. A perfect market mechanism could theoretically solve the question of “desirable safety.” But this does not happen for several reasons.
First, there is an information problem: the knowledge about seismic resistance cannot be made available for every structure. Second, the loss is not limited to the replacement cost of the building; the loss of a given building has additional economic effects. Third, the state is responsible for rescue and restoration after an earthquake.
