(Paul Wilmott) "We don't need more complex economics models... We need simplicity and robustness. We need to accept that the models of human behaviour will never be perfect. We need to accept all that, and then build in a nice safety margin in our forecasts, prices and measures of risk."
(Emanuel Derman) "what makes a good model and what makes a bad one", "models... are by definition not the real thing. They are simplifications... (Stock prices do NOT evolve lognormally). What is good simplification?"