Consumer Theory I Flashcards
What do Consumer Preferences tell us?
Tell us where Demand comes from
Helps explain how Consumers decide how much of Goods to Consume
What is the main Assumption we make about Consumption Bundles?
Consumption Bundles only contain 2 Goods
What is the Problem for the consumer with Consumption Bundles?
Consumer must choose between Different Bundles containing Different amounts of the same 2 Goods
What do Consumer Choices depend on?
Depend on their Preferences- i.e. Tastes
What are the 5 Axioms of Consumer Theory
Completeness + Transitivity- Define a utility Function given the Agent is Rational
Monotonicity + Local Nonsatiation + Convexity
What is Completeness?
Consumer can Rank Bundles
A is preferred to B, or Vice versa, or Indifferent
What is Transitivity?
Consumer’s Preferences are Logically Consistent
-If you want a Good now, you still want it later
What is Monotonicity?
Consumer always prefers More to Less
‘More is Better’
What is Local Nonsatiation?
You can ALWAYS find a Bundle y similar to x, but preferred to it
Weaker form of Monotonicity
What is Convexity?
People prefer Variety
How do you denote Bundle x is weakly preferred to bundle x1?
x ≥ x1
How do you denote x is strongly preferred to x1?
x > x1
How do you denote 2 bundles, x and x1, are Equivalent to each other- Indifferent
x ~ x1
When x is high, is a Consumer willing to give up More or Less for Good y?
More Willing
If Axioms Completeness + Transitivity are satisfied, what do people do when choosing bundles?
People Compare various bundles + decide on Utility Maximising Bundle
Define Utility Function
Relationship between Utility Measures + every possible Bundle of Goods
How do you denote the Utility Function for 2 Goods, x + y?
U(x, y)- given you can choose how much of each good you want to consume
It represents your Preferences
What 2 Measures can a Utility Function be?
Cardinal + Ordinal
When is a Utility Function a Cardinal Measure?
If we can give numbers to different levels of Utility + we can make Absolute Comparisons between those different numbers
e.g. Utility of 100 is 2x as much as Utility of 50
When is a Utility Function an Ordinal Measure?
If only ranking between different bundles matters
CANNOT make Absolute Comparisons
e.g. Utility of 100 is more than Utility of 50 but difference does NOT mean anything
What is required for a Utility to be Cardinal?
a Proper unit of Measurement
e.g. Unable to measure Happiness- so would be Ordinal
What does an Indifference Curve show?
Combination of all bundles that a Consumer sees as Equally desirable
-Bundles that give same level of utility
What is the Utility Function of 2 goods that are NOT perfect Substitutes?
U(x, y) = xy
So xy = Utility
What are the 5 main properties of Indifference Curves?
- Bundles further from Origin are Preferred to this on Ic closer to Origin- due to Monotonicity of Preferences
- There is an Ic through every possible Bundle- due to Completeness of preferences
- Ic CANNOT CROSS- Due to Transitivity
- Ic Slope DOWNWARDS- due to Strong Monotonicity
- Ic CANNOT be THICK- due to Local Nonsatiation + Monotonicity