Metrics characterising staggered payment schemes as depicted in Fig. 4, depending on the base payment p: Maximum spread H_max (black line), critical bonus b₁^(min) and b₂^(min) above which large spreads H can be observed (green and olive lines) and bonus b₂(H_max) where the spread H is maximal (blue line). H = is measured with respect to proportion q (H_q, panel a) and aggregation γ (H_γ, panel b). The values shown are averages over 100 randomly drawn cost landscapes.