BootChainLadder method different than England/Verrall

[loverway]

Correct me if I'm wrong, but it looks like the getExpected function is calculating the fitted triangle based on the Chain Ladder ultimates. This is different than England/Verrall Appendix 3 in which you "Obtain cumulative fitted values for the past triangle by backwards recursion, starting with the observed cumulative paid to date in the latest diagonal."

getExpected <- function(ults, ultDFs){ ults <- expandArray(ults, 2, dim(ultDFs)[2]) ultDFs <- expandArray(ultDFs, 1, dim(ults)[1]) return(ults * ultDFs) }

While the manual states "The implementation of BootChainLadder follows closely the discussion of the bootstrap model in section 8 and appendix 3 of the paper by England and Verrall (2002)", I think it's appropriate to note the difference in methods.