This only works when there are economies of scale. If there are significant dis-economies of scale smaller firms can out-compete the large firms. The large fir

This only works when there are economies of scale. If there are significant dis-economies of scale smaller firms can out-compete the large firms. The large firm can't just buy up all the small firms either because new firms are started all the time, and if every person who starts a small firm is rewarded with a buyout, the industry will attract more and more new firms until the large firm can no longer afford to buy out new firms. --------------- Examples of industries that not dominated by three or four large companies: mining, farming, house cleaning, and being a land lord.