Darwin College Lecture Series, University of Cambridge

Nassim Nicholas Taleb examines distributions whose behaviour is dominated by extremes and tail events. He classifies these distributions and identifies circumstances in which familiar statistical tools become unreliable, including slow or problematic convergence of sample averages under the law of large numbers. The lecture questions the robustness of commonly used statistical procedures in fat-tailed settings, the reliability of frequency-based forecasting, and the use of past averages as guides to future outcomes. Taleb then develops implications for decision-making and the changes in method needed when extreme observations have disproportionate influence.