Why do rms enter an industry when they know that in the long run economic prot will be zero? Firms would enter an industry if profit will eventually be zero because zero economic prot becomes positive once the value of the next best use of resources used in production is included. includes the opportunity cost of resources used in production and corresponds to negative accounting prot. 1:} A. B. {j} C. corresponds to positive producer surplus in the long run. D. indicates other industries are earning negative economic prot. E. signies that a rm is earning as much as it could in its next best activity