m8: Create an M8 type extension of the Cairns-Blake-Dowd...
In StMoMo: Stochastic Mortality Modelling

Description Usage Arguments Details Value References See Also Examples

Utility function to initialise a StMoMo object representing the M8 extension of the Cairns-Blake-Dowd mortality model introduced in Cairns et al (2009).

1	m8(link = c("logit", "log"), xc)

`link`	defines the link function and random component associated with the mortality model. `"log"` would assume that deaths follow a Poisson distribution and use a log link while `"logit"` would assume that deaths follow a Binomial distribution and a logit link. Note that the default is the logit link.
`xc`	constant defining the cohort age-modulating parameter.

The created model is either a logit-Binomial or a log-Poisson version of the M8 model which has predictor structure

η_{xt} = κ_t^{(1)} + (x-\bar{x})κ_t^{(2)} + (x_c-x)γ_{t-x}

where \bar{x} is the average age in the data and x_c is a predefined constant. Identifiability of the model is accomplished by applying parameters constraint

∑_cγ_c = 0.

An object of class "StMoMo".

Cairns, A. J. G., Blake, D., Dowd, K., Coughlan, G. D., Epstein, D., Ong, A., & Balevich, I. (2009). A quantitative comparison of stochastic mortality models using data from England and Wales and the United States. North American Actuarial Journal, 13(1), 1-35.

StMoMo, central2initial, cbd, m6, m7

M8 <- m8(xc = 89)
wxt <- genWeightMat(55:89,  EWMaleData$years, clip = 3)
M8fit <- fit(M8, data = central2initial(EWMaleData), ages.fit = 55:89)
plot(M8fit, parametricbx = FALSE)