reasons hmo is important why was joshua epstein important why is the paper about model important reasons why a model is constructed why model why model reasons to construct models why model why model santa fe, calif. how many reasons does epstein give why model reasons why a model can be built why use models reasons besides predicted why is epstein a modeler? why do you model reasons for modeling why do we need a model instead of prediction why are model and predict important who wrote the paper why models are a good example of how they are constructed reasons besides prediction to build models why use models