Index
The Demand Curve 1
The Demand Curve 2
The Demand Curve 3
The Laws of Supply and Demand - 4
The Laws of Supply and Demand - 5
A ''Contraction'' of Demand - 6
''Ceteris Paribus'' - 7
An ''Expansion'' of Demand - 8
Marginal Utility - 9
Marginal Utility - 10
Marginal Utility - 11
Marginal Utility - 12
Consumer Surplus - 13
Consumer Surplus - 14
Price Discrimination - 15
An ''Expansion'' of Supply - 16
An ''Expansion'' of Supply - 17
Market Equilibrium - 18
Market Equilibrium - 19
Market Equilibrium - 20
Movements of the Demand Curve - 21
Movements of the Demand Curve - 22
Movements of the Demand Curve - 23
Inferior Goods - 24
Movements of the Demand Curve - 25
Movements of the Supply Curve - 26
Movements of the Supply Curve - 27
Movements of the Supply Curve - 28
The Income Effect - 29
The Substitution Effect - 30
The Substitution Effect - 31
The Substitution Effect - 32
The Substitution Effect - 33
Complements - 34
Complements - 35
Review: Factors Effecting Demand - 36
Review: Factors Effecting Demand - 37
The Goals of Firms - 38
The Goals of Firms - 39
To: Elasticity

Complements - 35

Popcorn is a complementary good, when we consume the service called ''entertainment'' at the movies. Demand for popcorn has contracted, as a result of the increase in the price of the cinema ticket.

Previously, when the price of a movie ticket was $12, two hundred patrons bought popcorn per session. Now, as a result of the increase in the price of a movie ticket, only 170 people are buying popcorn; and to sell this quantity of popcorn, the cinema owners have had to decrease the price of popcorn to $1.70 per cup.

Economists argue that this effect is logical; people budget and plan their expenditures. Consumers will put aside a certain amount of money for the entire act of consumption; that is the movie ticket and any other associated expenditure. If the price of one part of the total consumption rises, consumers will reduce their expenditure on other parts of the act of consumption, to stay within their total budget.