Uncertainty appears to jump up after major shocks like the Cuban Missile crisis, the assassination of JFK, the OPEC I oil-price shock and the 9/11 terrorist attack. This paper offers a structural framework to analyze the impact of these uncertainty shocks. I build a model with a time varying...

Uncertainty varies strongly over time, rising by 50% to 100% in recessions and by up to 200% after major economic and political shocks. This paper shows that higher uncertainty reduces the responsiveness of R&D to changes in business conditions - a "caution-effect" - making it more persistent...

This paper shows that, contrary to common beliefs, the real options effect of uncertainty plays no role in the long run rate of investment. This is proven for both the standard investment model with Cobb-Douglas production and Brownian motion demand, and also for a broader class of models with...