Meaning of tail event | Babel Free

Definitions

1. an event associated with a given infinite sequence Y=y_k|k>k_0 that is determined by any subsequence of the form Y_n=y_k|k>n,n>k_0 (a "tail" of that sequence)
2. a low-probability event
3. an event that initiates an activity

Examples

“Exactly two years later, it was shattered by the force of a tsunami equivalent to the impact of 250 jumbo jets flying at 1,000 kilometers an hour—the very apotheosis of a real tail event.”

“... When the MS index is high ex ante, subsequent large stock market losses and crashes are no longer tail events at all—rather they are perfectly expected events.”

“Policy frameworks anticipating only “ordinary” shocks within the usual economic cycles may not be very effective in mitigating the impact of such tail events when they actually materialize.”

CEFR level