These slides are from one of the best sessions I attended at scifoo. Bill Janeway's perspective was both theoretical and historical, but in addition we had Sam Altman of Y Combinator to discuss Airbnb and other examples of 2 way market platforms (Uber, etc.) that may be enjoying speculative bubbles at the moment.
See also Andrew Odlyzko (Caltech '71 ;-) on British railway manias for specific cases of speculative funding of useful infrastructure:
here,
here and
here.
