WE REFERRED HERE to "profit in the economic sense." Just as "rent" and "interest" are different in their economic meanings than in normal conversation, the same is true of "profits." In normal parlance, profit is understood as simply the amount a business takes in, minus the amount it spent. "Economic profit" is a bit more complex -- it is generally understood as the amount taken in minus the opportunity costs -- the next highest-yield alternative use -- of all the factors used. This is why "economic profit" is seen as a measure of business acumen. Some economists have pointed out that in a perfectly competitive market, "economic profit" would necessarily be zero -- and that therefore it is a measure of how much someone has taken advantage of imperfect competition. In this, as in so many other economic matters, fuzzy definitions lead to confusion.