Fig. 4.

The strategic responses and corresponding dynamics change with the number of hospitals that interact. (a) The response curves (solid) for increasing n. The strategic optimum, the points at which a focal hospital's optimal investment matches the investment of other hospitals, decreases with n (the dashed line shows equal investments). Note also that the coordinated optimum for many hospitals is the same as the optimum investment for a single hospital, n = 1. (b) These decisions affect the rate at which resistance increases. For n = 10, an epidemic occurs if hospitals allocate at the strategic optimum, whereas the coordinated optimum prevents emergence for more than a decade. Hence, the epidemic will be delayed and less severe in isolated areas. The transmission function here is the same one used for Fig. 2, with 1/λ = 2,000 days and 1/r ≈ 1,500 days.