Figure 1.

Examples of the relationship between (a) log mortality and age (a) and (b) mortality against age according to the Gompertz–Makeham equation (equation (1.2)). The four cases shown have parameter values as follows: a: α = 0.01, β = 0.1, γ = 0; b: α = 0.01, β = 0.15, γ = 0; c: α = 0.02, β = 0.1, γ = 0; d: α = 0.01, β = 0.1, γ = 0.1.