Let the number X of accidents have a Poisson distribution with mean 
. Suppose λ, the liability to have an accident, has, given θ, a gamma pdf with parameters α = h and 
; and θ, an accident proneness factor, has a generalized Pareto pdf with parameters α, λ = h, and k. Show that the unconditional pdf of X is
sometimes called the generalized Warring pmf.