In economics, competitive means perfect, and non-competitive means imperfect. Only in the perfectly competitive market, P=MR=MC which can lead to optimum. It will be efficient because no excess output and cost. The world market of agricultural products is mostly declared perfectly competitive. On the contrary, in the imperfect world, MR=MC, it will lead to high price and high cost, but also high profit. Such as Pepsi and Coke, Air Bus and Boeing. Retail stores are likely to be monopolistic competition. Microsoft was declared as monopolist.
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