Marvin owns Merry Marvins Merry Go Rounds. He works out of the garage at his home. Since his business is booming, he uses the whole garage to make and sell merry-go-rounds.

If Marvin hires an accountant to determine his profits, his accountant is likely to determine a higher profit than Marvin would determine if he used economic theory to determine his profit. What is the difference, and why would his accountant come up with a greater profit than an economist would calculate?