What is the utility function for Perfect Substitutes?
U(x1,x2)=ax1+bx2U(x1,x2)=ax1+bx2
What is the shape of the indifference curves for Perfect Substitutes?
Downward sloping straight lines.
What is the utility function for Perfect Complements?
U(x1,x2)=min(ax1,bx2)U(x1,x2)=min(ax1,bx2)
What is the shape of the indifference curves for Perfect Complements?
L-shaped lines (or “intersecting lines” forming right angles).
What is the general form of a Quasi-linear utility function?
U(x1,x2)=f(x1)+x2U(x1,x2)=f(x1)+x2
What is the key visual characteristic of Quasi-linear indifference curves?
They are vertical shifts of each other (they have the same slope).
What is the general form of a Cobb-Douglas utility function?
U(x1,x2)=x1cx2dU(x1,x2)=x1cx2d
How are Cobb-Douglas indifference curves described?
Well-behaved and strictly convex.
What is a Marginal Utility?
The additional utility gained from consuming one more unit of a good.
What is the formula for the Marginal Rate of Substitution (MRS) using marginal utilities?
MRS=−MUx1MUx2MRS=−MUx2MUx1
What is the MRS for a Cobb-Douglas function U(x1,x2)=x1cx2dU(x1,x2)=x1cx2d?
MRS=−cx2dx1MRS=−dx1cx2
What is Ordinal Utility?
Only the ranking of utility matters; the magnitude of the difference between values is not meaningful.
What is Cardinal Utility?
The magnitude and difference between utility values are meaningful.
What is the purpose of a Monotonic Transformation of a utility function?
To create a new function that represents the same underlying preferences.
What is the key property that is preserved under a monotonic transformation?
The MRS (the slope of the indifference curve) remains the same.
What is the fundamental requirement for any utility function?
It must preserve the original preference relations of the consumer.
If two bundles have the same utility value, what does this imply?
The consumer is indifferent between the two bundles.
What is the relationship between utility functions and indifference curves?
An indifference curve connects all bundles that yield the same utility level.