shocks to aggregate uncertainty, I introduce a small, time-varying risk of economic disaster in a standard real business … cycle model. The paper establishes two simple theoretical results: first, when the probability of disaster is constant, the … risk of disaster does not affect the path of macroeconomic aggregates - a "separation theorem" between macroeconomic …

-varying risk of economic disaster. Both asset prices and macroeconomic aggregates respond to this time-varying risk. The model is … prices. An increase in the risk of disaster leads to a collapse of investment and a recession, with no current or future … risky securities increase. To assess the empirical validity of the model, I infer the probability of disaster from observed …