Term One Flashcards
What does A>~B mean?
What happens it B>~A is also true
What if the middle statement is not true?
The top means the A is weakly preferred to B.
if the bottom is true it means they are different
It means that A is strictly preferred to B A>B
What must hold true for rationality to hold true? Define these two concepts.
Completeness: We must have either A>~B or B>~A or both
Transitivity: if A>~B and B>~C then A>~C
Both of these hold true for rationality.
Define the concepts of ; Monotonicity and convexity.
Monotonicity: Implies that people prefer more than less (max)
Convexity: Suggests that the average of two bundles is better than all of one or the other (interior solution rather than corner)
How to map utility functions?
Rearrange the function to be a function of Y and X, then sub in values of K (which you choose) to give the curves.
What does A~B mean?
It means that the individual is indifferent between A and B
What is the tangency equation in consumer optimisation
MRS=Px/Py
How to test for convexity?
Take the MRS and it should be decreasing in X and increasing in Y
How to test for an interior Solution
Point A: Find Y=M/Py and X=0
MUx/Px > MUy/Py
Point B: Find X=M/Px and Y=0
MUy/Py > MUx/Px
Draw a diagram to show the effect of an income increase for goods when X and Y, when;
Both goods are normal
X is an inferior good
Normal both increases normally and shifts out parallel
X inferior
It will cause X to decrease and Y to increase further.
Draw a diagram to show the effect of a price increase in X.
Show what would happen with different set of preferences.
There will be less X consumer firstly.
Then even more less X and higher Y.
Plot indifference curves and budget constraints for perfect complements and given the utility function
Diagram where ax=By and there is right angles through this line. Then a budget constraint.
U(X,Y)=Min{ax,BY} Px, Py, M
What is shown by a demand curve?
A demand curve shows how much an individual will consume at a given price.
What is shown by an Engel curve.
An Engel curve shows how much an individual will consume at each level of income.
How to derive;
- Demand Curve
- Engel Curve
Take preferences, utility function and prices for goods X and y. Then plot down the level of X consumed for different levels of utility X1, X2, X3.
- Demand, trace the levels to prices, P1 is highest to X1.
- Engel, trace the levels to income, M1 is the lowest to X1.
How to derive a demand function.
What does the demand function contain?
Use the tangency condition and sub in the result to the budget constraint.
it shows information from both the demand curve and the Engel curve.
What does a Straight Engel curve show?
What is an example
It shows the presence of Homothetic Preferences.
This is where the demand increases in line to income .
Perfect Complements are an example.
Draw a demand curve and engel curve for quasi-linear utility
Income less than aPy/B will all spend on X and nothing above this.
Then the curve for Y will be the opposite, where things above aPy/B all will be spent on Y.
Classify;
- Inferior Good
- Homothetic
- Normal Goods
- Necessary Goods
- Luxury
Inferior: if income increases demand decreases.
Normal: if income increases demand increases
Homothetic: income and demand increase proportionally
Necessary: demand increases less than proportional than income.
Luxury: Demand increases greater than proportional than income
Outline what happens (two effects) from an increase in price of good X.
Substitution Effect; X becomes more expensive relative to Y. This means consumers will substitute Y in place of X.
Income Effect; Consumers have relatively less income, they will change their consumption amounts of both goods.
What effects does the Marshallian Demand curve show?
How do you isolate the substitution effect
It shows both substitution and income effects.
Sub effect is isolated by finding the real income level.
Give two measures of REAL income
Slutsky: The Purchasing power of the income.
Hicks: The utility that the income provides.
What is shown by a Hicksian Demand curve?
it shows the change in demand for a good, as a result of a price change. Keeping the utility of the consumer constant.
What is shown by the Slutsky demand curve?
It shows the change in demand of a good as a result of a price change. When purchasing power is kept constant..
Derive the demand curve for Slutsky and Hicks
Find the asnwers at Micro Lecture 7, slide 9-11
Is consumer surplus a good measure of welfare?
Consumer surplus is an inexact measure of welfare.
This is because the Marshallian Demand curve shows the consumer’s demand for a good with a fixed amount of nominal income.
Price changes will also change the value of real income.
It does not show a consumer’s true valuation of the goods.
What is compensating variation?
Following a price change it is the income change that would be required for a consumer to move back to their original indifference curve that they were on before the price change.
What are the axis labels for a CV and EV diagram?
Good x on x axis
Money on Y axis.
Draw a CV diagram
Lecture 8 slide 17
What is Equivalent Variation (EV)
It is the change in income, with constant prices, that would have the same effect on consumer welfare as a change in the prices with the income constant.
What effect on the budget constraint does
- Compensating Variation
- Equivalent Variation
have.
- CV: Will cause a shift out of BC, parallel to new prices.
- EV will cause a shift inwards of BC, parallel to old prices.
How to graphically represent CV, EV , CS
Lecture 8 slide 26-30
How to work out CV and EV
CV: old utility new prices
EV: New utility Old prices.
How to find Hicks and Slutsky
Hicks: Keep utlity constant and solve utliity function for new M, using demand functions found first.
find new demand AMOUNTS (remember demand functions cannot change).
Slutsky: Using old amounts and new prices, use budget constraint to find new income.
Use new income to find new demand amounts.
Use the change in demand amounts to calculate the substitution effect.
What is an individal’s budget equation with respect to labour supply?
pY+(T-L)w = M +Tw
Where L represents Leisure,
therefore T-L is the amount of hours worked.
What does w represent?
It is the rate at which she sells her labour hours and buys her leisure time.
Draw the budget constraint for labour market.
Straight gradient from Y intercept (M+Tw)/P. down to a point where M/P. Then straight down to x axis, where leisure is T hours.
If x is the number of leisure hours, express the budget constraint for this.
(M+(T-X)w)/P
What happens if there is an increase in non-labour income?
It will cause the budget constraint to shift straight upward from M to M1.
Which effect dominates at each job wage level?
High wage: Income effect.
Low wage: Substitution Effect.
What is the effect of;
Lowering Government benefits?
Raising Income Tax?
GB: will be the same as reducing non-labour income. Therefore, there will be less leisure.
IT: It is the same as reducing the wage rate, this will mean less leisure.
What is the effect of an decrease in the interest rate?
Ambiguous for lenders
Lower C1 for big lenders as income effect will dominate substitution effect.
Raises C1 for borrowers
What is the effect of a increase in interest rate?
Lowers C1 for a borrower.
increases C1 for big lenders.
What can be classed as uncertainty in the consumer choice model.
not sure of the quality of the product.
not sure of the state of the future environment.
Financial risk is embedded in the actual product, i.e; a financial asset.
What must be true about states of the world?
Only one can occur
at least one must be true in the future.
Give two examples of state contingent commodities.
Insurance,
Financial assets
What clothes you choose to wear.
Investment decisions
What is a contingent consumption plan?
it is something which specifies what you will consume in each state of the world.
how do you apply consumption theory to uncertainty situations?
you will have your different levels of consumption as different states of the world.
mishap wealth
no mishap wealth
for example.
How do you find the budget constraint under uncertainty?
You equal the contingent consumption plans and solve
how to you find the prices in uncertainty.
You can see on the budget constraint that they are in the form xpx+ypy=M
Slope of budget equation = -px/py.
What is the general form of utility functions for an uncertainty problem?
U(X,Y) =piex V(x) + piey V(Y)
Pie is the probability if the state of the world.
V is the expected utility function. It is an increasing function.
V is known as a Bernoulli Utility function.