Effect of SMS-EMOA Parameterizations on Hypervolume Decreases

It is possible for the (μ+1)-SMS-EMOA to decrease in dominated hypervolume w.r.t. a global reference point. We study the influence of SMS-EMOA parameter settings on number and amount of the observed decreases. We show that the number of decreases drop and the number of increases rise with a higher population size. In addition, a positive correlation between mean increase and mean decrease can be observed. Our findings further indicate a substantial impact of the mutation operators on the number and amount of decreases.