  In this article, the parameters of a hybrid log-linear model (log-Poisson)
are estimated using the fuzzy least-squares (FLS) procedures (Celmi\c{n}\v{s},
987a,b, D'Urso and Gastaldi, 2000, DUrso and Gastaldi, 2001). A goodness of fit
have been derived in order to assess and compare this new model and the
classical log-Poisson regression in loss reserving framework (Mack, 1991). Both
the hybrid model and its goodness of fit are performed on a loss reserving
data.
