 Unobserved heterogeneity in duration models

Unobserved heterogeneity in duration models refers to the variation in the duration until an event occurs (such as failure, death, or completion) that cannot be directly observed or measured but still affects the duration of the event. In other words, it accounts for individual differences that influence the time until an event that are not captured by the observable variables in the model. Duration models, also known as survival or timing models, are statistical models used to analyze time-to-event data.