As with the string quartet example, it takes nurses the same amount of time to change a bandage, or college professors the same amount of time to mark an essay, in 2006 as it did in 1966.

http://en.wikipedia.org/wiki/Baumol%27s_cost_disease

This is because those types of activities rely on the movements of the human body, which cannot be engineered to perform more quickly, accurately or efficiently in the same way that a machine, such as a computer, can.