Input Market Substitutes

The Wall Street Journal has an interesting article on input market substitutes for health care patient sedation:  using a machine to sedate patients instead of a anesthesiologist.  Economically we can address which is more cost efficient if we take a look at the marginal product of each per dollar spent on each input and choose the one that has a higher marginal product per dollar in cost.

In the article we see that anesthesiologist's cost between $600 to $2000 per procedure and the machine would cost $150.  If the marginal product is similar, then the machines are substantially more cost-efficient.