The following similarities and dissimilarities are found in monopolistic and monopolistic competition markets :

Similarities :

1. In both markets, the equilibrium lies on the point where marginal cost and marginal revenue are equal (MC = MR).
2. In both the markets, the demand curve or the average revenue (AR). curve slopes downward from left to right, and the marginal revenue (MR) curve is below it.
3. In both markets, the equilibrium price of the product is more than its marginal cost.
4. Producers have control on the price of product in both markets. He can make slight changes in the product’s price, as per his wish.
5. In both markets, the equilibrium, point is below the average revenue curve.
6. In both markets, firms produce less than the optimum quantity. Hence, they have additional capacity of prodution.

Dissimilarities :

1. In a monopoly there is only one producer firm, while in monopolistic competition, the number of firms is more.
2. No product differentiation is done in monopolistic market, while it is a key feature in monopolistic competition.
3. There is more of firm’s control on product pricing in a monopoly, since there is no competition, while in monopolistic competition, the firm does not have such absulute control over price, since it has to compete with a number of firms in the market.
4. The demand curve of a monopolistic firm is of a steeper slope, while the demand curve in a monopolistic competition has a less steeper slope.
5. In monopolistic market, the firm receives extraordinary profit in the long term, while in monopolistic competition, the firm receives only normal profit in the long term.
6. A monopolist can adopt the policy of price discrimination, but this is not possible in a monopolistic competition.
7. In a monopolistic market, the price of the product is found to be the same in the entire market, since a single product is produced by a single firm, but because of product differentiation in a monopolistic competition market, prices of products may be different.
8. Sales costs are not generally found in monopolistic market, while in monopolistic competition, sales costs are significant due to mutual competition among firms.