Rather than trying to dictate/engineer a "fault tolerant" economy, I suggest thinking more along the lines of "what
simple mechanisms can be put in place in how the system functions so that participants in the markets/economies can make better decisions?"
Two things that I think are critical:
* true transparency (e.g., look at the CDS fiasco ("look, it's insurance but it's not!" and the complete lack of reporting)
* rate limiters (e.g., look at how much the recent volatility is due to the frantic rushing around, the reaction to all of that franticness, etc. For the physics enthusiasts in the crowd think of the propagation of supernovae through a given volume of a galaxy)