Figure 2-5 A, The hypothetical relationship between inputs to a productive process and the benefits derived describes a production function. As investment continues, the net benefit, segment ΔBⁿ , progressively decreases and then becomes negative, illustrating the law of diminishing returns. B, Rationalizing rather than rationing health-care technology achieves maximal benefit at "the top of the curve," a level of investment associated with the optimal investment. (A is reproduced from Orkin^[45] ; B is modified from Orkin^[45] and Reinhardt.^[46] )