Economics is about allocation of limited resources to their best use. Similar to the rest of economy, healthcare sector must follow certain criteria in allocating limited resources (inputs) such as hospital services, pharma, RN services, physician services etc. to production of medical care. Explain why in economic thinking, we are concerned about ‘marginal' or ‘incremental' contribution of input(s) to output and not ‘total' contribution of inputs. Also discuss the economic law the captures the logic for tracing ‘marginal' input contribution to output.