  A theoretical analysis of the earthquake prediction problem in space-time is
presented. We find an explicit structure of the optimal strategy and its
relation to the generalized error diagram. This study is a generalization of
the theoretical results for time prediction. The possibility and simplicity of
this extension is due to the choice of the class of goal functions. We also
discuss issues in forecasting versus prediction, scaling laws versus
predictability, and measure of prediction efficiency at the research stage.
