Sample Questions
The Akaike Information Criterion is defined as: where is the maximized log-likelihood and is the number of estimated parameters. The criterion balances fit (via ) against complexity (via ). Lower AIC is preferred.
AIC penalizes each parameter by . BIC penalizes each by . The BIC penalty exceeds AIC's when , i.e., . For any dataset with — which includes virtually every actuarial application — BIC penalizes additional parameters more heavily than AIC and therefore selects simpler (fewer-parameter) models.
The survival function is . By the delta method: At , : .