Answer:
summing horizontally the segments of the MC curves lying above the AVC curve for all firms.
Explanation:
In a perfect competition, there are many buyers and sellers of homogeneous products, and there is free entry and exit in the market.
This simply means that, in a perfectly 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.
Generally, a perfectly 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.
The short-run supply curve for a purely competitive industry can be found by summing horizontally the segments of the marginal cost (MC) curves lying above the average variable cost (AVC) curve for all firms.
