(a) If labour productivity, δ, is sufficiently high, then all initial conditions lead to high income and low disease burden. (b) If δ is sufficiently low, then all initial conditions lead to low income and high disease burden. α = 0.06; β̄ = 40; μ̄ = 0.01; ν = 0.02; h̄ = 90; δ = 5; ϱ = 0.003; τ = 0.15; ϕ = 15; κ = 30. Black line, I*(M); grey line, M*(I); dotted grey line, M*(I).