[lucianbr]

It's a perfectly good measure except it does not help us at all.

The whole reason for this discussion is situations like Microsoft having 200k employees and making $240B in a year. Which employees, teams, or even departments are more productive? They want to know.

And even if it did not matter, likely the expense of this year influences the income over multiple future years, so you compare the dollars in / dollars out for which periods?