We consider forecasting from age-period-cohort models, as well as from the extended chain-ladder model.  The parameters of these models are known only to be identified up to linear trends.  Forecasts from such models may therefore depend on arbitrary linear trends.  A condition for invariant...

It has long been known that maximum likelihood estimation in a Poisson model reproduces the chain-ladder technique.  We revisit this model.  A new canonical parametrisation is proposed to circumvent the inherent identification problem in the parametrisation.  The maximum likelihood estimators...

We consider forecasting from age-period-cohort models, as well as from the extended chain-ladder model. The parameters of these models are known only to be identified up to linear trends. Forecasts from such models may therefore depend on arbitrary linear trends. A condition for invariant...

An algorithm suggested by Hendry (1999) for estimation in a regression with more regressors than observations, is analyzed with the purpose of finding an estimator that is robust to outliers and structural breaks.  This estimator is an example of a one-step M-estimator based on Huber's skip...