With identical firms, constant input prices, and all the other characteristics of a competitive market ______. Group of answer choices a shift in demand has no effect on the long-run average cost, resulting in a change in equilibrium price but not quantity a shift in demand has no effect on the long-run average cost, resulting in a change in equilibrium quantity but not price a shift in demand will change the equilibrium price and quantity a shift in demand has no effect on the long-run average cost and so there is no change in equilibrium price and quantit