"While there are many reasons why we failed to predict the crisis, one of the major ones is arguably that for the last several decades economic thinking was dominated by neoclassical economics, which some describe as an “idealized vision of an economy in which rational individuals interact in perfect markets.”
The financial crisis may have done for this idealized view of people and markets what the atomic spectrum and speed of light experiments did for classical mechanics at the end of the 19th century. They have both acted as kinds of turn of the century indicators that the world out there is far more complex than previously imagined, and new theories and models are now needed."
Social sciences with formulae are still non-deterministic.
"How do you then deal with these highly unpredictable complex systems in our midst?"
- http://blog.irvingwb.com/blog/2010/04/a-21st-century-magical-mystery-tour.html (view on Google Sidewiki)