porter 1980 five forces
in the economists’ “perfectly competitive” industry, jockeying for position is unbridled and entry to the industry very easy. the strongest competitive force or forces determine the profitability of an industry and so are of greatest importance in strategy formulation. economies of scale can also act as hurdles in distribution, utilization of the sales force, financing, and nearly any other part of a business. the causes of the decline in unit costs are a combination of elements, including economies of scale, the learning curve for labor, and capital-labor substitution. all this suggests that the experience curve can be a shaky entry barrier on which to build a strategy.