Abstract
This paper examines the problem of
accurately estimating the expected value and variance of aggregate claims for
each policyholder. Through an appropriate statistical model to estimate the
pure premium, an insurer can find niche markets to operate competitively and
profitably. To this end, the framework of generalized linear models (GLMs) for
aggregate claims is extended to encompass a species of frequentist generalized
additive models (GAMs) based on cubic penalized regression splines. The new
structure could allow for the incorporation of more flexible nonlinear and/or
nonparametric trend terms for the marginal claim frequency, conditional claim
severity, and finally for Tweedie modelling as well. This nonparametric
approach is illustrated through simulation and applied to an automobile
insurance dataset. A juxtaposition of hypothesis test results, AIC values, and
attendant graphical diagnostics effectively demonstrate that the GAMs under
both the independent and dependent settings give a better fit than the GLM
approach.
JEL classification numbers: C14, G22.
Keywords: Premium, Generalized Additive Models, Dependence, Splines,
Frequency, Severity.