## Learning Objectives

• Concept of total revenue in Perfect Competition and monopoly
• Concept of average revenue in Perfect Competition and Monopoly
• Concept of Marginal Revenue in Perfect Competition and Monopoly
• Derivation of TR, AR, and MR curve using tabular data

### Total Revenue

Total revenue can be defined as the total amount of money earned by the firm by selling the output produced. The total revenue of any firm can be determined by multiplying the price per unit and total quality sold by the firm.

In case of perfect competition,

• Total Revenue (TR) = Price (P’) x Total Quantity (Q) [where P’ is a constant price]

In case of monopoly,

• Total Revenue (TR) = Σ(P x Q) [Where P is a variable price]

### Average Revenue

Average revenue can be defined as the amount of money earned by the firm by selling per unit output produced. The average revenue is also the demand curve of the firm because demand curve shows the relationship between average price and the quantity demanded. Mathematically, Average revenue equals to Total revenue divided by quantity sold.

In case of perfect competition,

• Average revenue = TR/Q = (P x Q)/Q = P

In case of monopoly,

• Average Revenue = TR/Q = Σ(P x Q)/ΣQ

### Marginal Revenue

Marginal Revenue can be defined as the change in total revenue due to one unit change in quantity sold.

In case of perfect competition,

• Marginal Revenue = ΔTR/ΔQ = P x ΔQ/ΔQ = P [Price is constant in Perfect Competition]

In case of monopoly

• Marginal Revenue = ΔTR/ΔQ

### Tabular Analysis

• Perfect Competition
 Price (P) Quantity (Q) TR (P x Q) AR (TR/Q) MR (ΔTR/ΔQ) 100 100 10000 100 100 100 200 20000 100 100 100 300 30000 100 100 100 400 40000 100 100 100 500 50000 100 100 100 600 60000 100 100 100 700 70000 100 100 100 800 80000 100 100 100 900 90000 100 100 100 1000 100000 100 100 The average revenue equals to price and is parallel to quantity axis. The average revenue is horizontal because the firm is price taker not the price maker.

• Monopoly
 Price (P) Quantity (Q) TR (P x Q) AR (TR/Q) MR (ΔTR/ΔQ) 1000 100 100000 1000 1000 900 300 270000 900 850 800 500 400000 800 650 700 700 490000 700 450 600 900 540000 600 250 500 1100 550000 500 50 400 1300 520000 400 -150 300 1500 450000 300 -350 The average revenue in monopoly slopes download because the monopolist has control over either price or quantity; he or she has to choose between price or quantity. There is trade-off between price and quantity, so if he or she wishes to increase the price, then he or she must accept the fall in quantity demanded and vice-versa.