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 were inevitably going to strike the region again, and reinforcement of new buildings would certainly mitigate future losses. Consequently, building codes were established in 1933, resulting in today’s Uniform Building Code still in a process of evolution. Increasingly stringent requirements have led to higher and higher costs of construction. As a result, several important questions have arisen: What is 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 It he marginal return of still more stringent codes? Other questions concern techniques for prediction of earthquakes: identification, monitoring, and understanding of precursor signals.
On 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 could be triggered by a long term, credible prediction. On the other hand, a successful prediction could save many lives, perhaps at a lower cost than that associated with more stringent building requirements.
Given the present state of building practice and foreseeable improvements in prediction techniques, what are the probable costs and benefits of earthquake prediction? 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 decision 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 essentially responsible for rescue and restoration after an earthquake.