firms
Question
One could argue correctly that:all firms in any industry can earn short-run but not necessarily long-run
positive economic profit.
all firms in any industry can earn long-run but not necessarily short-run positive economic profit.
all firms in any industry can earn both short-run and long-run positive economic profit.
no firm in any industry can earn long-run positive economic profit because all price changes made by any firm will be followed by all of the other firms.
all firms in any industry can earn short-run positive profit if economies of scale exist.