An important similarity between a monopolistically competitive firm and a purely competitive firm is that:-a. realize an economic profit in the long run. b. achieve allocative efficiency. c. face demand curves that are less than perfectly elastic. d. achieve productive efficiency.

a. realize an economic profit in the long run.

Explanation:

A monopoly is a market structure which is typically characterized by a single-seller who sells a unique product in the market by dominance. Thus, it is a market structure wherein the seller has no competitor because he is solely responsible for the sale of unique products without close substitutes. Any individual that deals with the sales of unique products in a monopolistic market is generally referred to as a monopolist.

Hence, one of the ways in which some monopolistic competitors try to become more like monopolists is through the use of designer labels.

This ultimately implies that, when there are barriers to entry it may result in monopolistic competition among the sellers of goods having no close substitutes. These barriers consist of economies of scale, network externalities, copyright law, trademark, patent, governmental policies etc.

In a purely competitive market, there are many buyers and sellers (price takers) of homogeneous products (standardized products with substitute) and the market is free (practically open) to all individuals or business entities that are willing to trade all their goods and services.

Hence, a purely competitive market is characterized by the following features;

1. Perfect information.

2. No barriers, it is typically free.

3. Equilibrium price and quantity.

4. Many buyers and sellers.

5. Homogeneous products.

An important similarity between a monopolistically competitive firm and a purely competitive firm is that realize an economic profit in the long run and these profits tends toward zero as both firms continue in the market.