The scientific study of complex systems has transformed a wide range of disciplines in recent years, enabling researchers in both the natural and social sciences to model and predict phenomena as diverse as earthquakes, global warming, demographic patterns, financial crises, and the failure of...

We present a self-consistent model for explosive financial bubbles, which combines a mean-reverting volatility process and a stochastic conditional return which reflects nonlinear positive feedbacks and continuous updates of the investors' beliefs and sentiments. The conditional expected returns...

We present a novel methodology to determine the fundamental value of firms in the social-networking sector, motivated by recent realized IPOs and by reports that suggest sky-high valuations of firms such as Facebook, Groupon, LinkedIn Corp., Pandora Media Inc, Twitter, Zynga. Our valuation of...

The opposition in a number of countries to the inclusion of nuclear energy in a sustainable energy portfolio, in part due to the dread of what the “nuclear” word inspires, has limited quantitative scientific foundation of the real benefits and risks. This has been amplified by the lack of a...

We present strong evidence that financial bubbles can be identified ex-ante and that a sharp price increase, when suitably qualified by a bubble indicator called LPPLS confidence, does on average predict unusually low returns going forward. For this, we use a methodology called log-periodic...