垄断与竞争不同的产业有不同的市场结构。结构特征中最关键性的因素是卖主的集中、产品差异和新卖主进入该产业的难易。其中最能影响市场结构的因素是卖主的集中程度，包括以下三类。一是小经营者竞争，即卖主很多，各个卖主的市场份额很小，谁也难以通过改变价格或产量来... Industries with different monopolies and competition have different market structures. The most crucial factor in the structural characteristics is the concentration of vendors, product differentiation and the difficulty of new vendors entering the industry. The most influential factor in the market structure is the concentration of vendors, including the following three categories. One is the competition of small operators, that is, there are many vendors and the market share of each vendor is small, and it is hard for any one to change prices or output to ...