Questions tagged [consumer-theory]

the study of consumer choice and its fundamental underpinnings in preferences and constraints.

3
votes
1answer
390 views

Optimization problem with Kuhn-Tucker conditions

Consider a game with two players where each player $i=1,2$ has preferences $u_i=s_i^a c_i^{1−a}$, where $c_i$ is consumption and $s_i$ is social interaction. $s_i$ is given by $s_i=t_i+t_{ij}\times t_{...
10
votes
2answers
24k views

Marshallian Demand for Cobb-Douglas

When trying maximize the utility having a cobb-douglas utility function $u=x_1^ax_2^b$, with $a+b = 1$, I found the following formulas (Wikipedia: Marshallian Demand): $x_1 = \frac{am}{p_1}\\ x_2 = \...
14
votes
3answers
159 views

Current knowledge about the empirics of consumer theory

I would like to get up to speed on the current state of empirical work done to test the assumptions and predictions of consumer theory (think Chapters 1, 2, 3, and 6 of Mas-Colell et al.). Can anyone ...
9
votes
6answers
871 views

Piracy/File sharing - Why aren't songs, movies or books given for free?

Why aren't songs, movies or books given for free (+ads)? i. Every minute, people are pirating and there is no stopping that. If people see 0.99 for a song on iTunes and 0.00 for a song on a torrent ...
23
votes
4answers
2k views

What are Giffen Goods?

What exactly are Giffen goods and are they of purely theoretical interest or has there been empirical evidence of their existence?
8
votes
2answers
861 views

When can one safely talk about decreasing marginal utility?

One thing I hear a lot is talk of decreasing marginal utility—the idea being that additional units of a good become progressively less attractive the more units of that good one has already. However, ...
6
votes
3answers
6k views

What is a rational consumer?

There is a lot of debate on whether or not consumers and investors are rational. Unfortunately, I haven't seen much qualification for what is called a rational consumer. What are the requirements ...
6
votes
3answers
2k views

Which utility function yields a constant price elasticity of demand function?

How do I know which utility function I can use to find an isoelastic demand function, e.g., $x(p)=Ap^a$? And similarly, which cost function can I use to find an isoelastic supply function? Does it ...
12
votes
2answers
10k views

The relationship between the expenditure function and many others!

I dont understand the relationships between Hicksian demand, walrasian demand (marshallian), the expenditure function and the indirect utility function (including the value function V(b)). I have ...
5
votes
2answers
8k views

Why is the income effect zero for quasilinear utility functions?

Suppose I have the utility function $$U(x,y) = \sqrt{x} + y$$ subject to budget constraint $$p_x x + p_y y = m$$ Then $$x_M =\frac{p_y^2}{4 p_x^2}$$ $$y_M = \frac{m}{p_y} - \frac{p_y}{4 p_x}$$ ...
15
votes
3answers
1k views

Are monotonic and continuous preferences necessarily rational?

Let $\succsim$ be a strictly monotonic and continuous preference relation, and let $X=\mathbb{R}^{n}$ be the consumption set. Is rationality of $\succsim$ implied by these conditions? I think ...
-2
votes
1answer
204 views

Question on consumer theory

The story of my question is I have multiple question. (1) when John doesn’t work in the underground economy at all , t=0, how can I find the optimal value of $l$ and consumption bundle and his ...
4
votes
1answer
138 views

Why does $\varepsilon_{x,p_x}^H =-s_y \sigma $?

Suppose I have two goods $x$ and $y$ and their associated prices $p_x$ and $p_y$. Income $m$. $x^H$ is Hicksian demand and $x^M$ is Marshallian demand. Slutsky Equation: $$\frac{\partial x^M}{\...
3
votes
4answers
366 views

what is consumer surplus practically?

In Microeconomics producer surplus is equivalent to profits minus fixed costs. However getting a tangible definition of consumer surplus has been difficult for me to ponder. What is the practical ...
3
votes
1answer
2k views

(Preference Relation/Set) Continuous $\succsim$ imply closedness of upper and lower contour sets

[ADDED/MODIFIED] : I have put my proof where the commodity space is simply $\mathbb{R_+}$(e.g. nonnegative reals) for simplicity below. Please share your 2 cent. I have put words to aid my own ...
6
votes
1answer
689 views

Does a monotonic transformation of a homothetic utility function imply the preference relation on the set of consumption bundles is still homothetic?

Does a monotonic transformation of a homothetic utility function imply the preference relation on the set of consumption bundles is still homothetic? Obviously, if a utility function on a set of ...
6
votes
1answer
2k views

Do perfect complements have to be normal goods? If so, why?

Two goods $x,y$ are perfect complements if they have the utility function $$U(x,y) = \min \lbrace ax,by \rbrace $$ $$a,b \in \Bbb{Q}^+$$ My professor said $x,y$ have to be normal goods but didn't ...
5
votes
1answer
153 views

What are the economic benefits of SLAPP in file sharing/piracy?

Spin-off from Piracy/File sharing - Why aren't songs, movies or books given for free? What are the economic benefits of SLAPP in or out of file sharing/piracy? There's a comment in above link ...
5
votes
2answers
754 views

Why do so many models assume homothetic preferences?

...when Engels Law, backed by a good amount empirical evidence, demonstrates that overall consumer preferences are not homothetic. See for example, Jorgenson (1997)
5
votes
2answers
343 views

Does consumer theory assume that utility functions are consistent overtime?

I'm interested in how we model a consumer with a changing utility function over time. Example: an individual's demand for candy/sweets at 10 years of age will be different when he is 20,30 or 40 ...
4
votes
2answers
1k views

Meaning of Additively Separable, Linear in X

Often I see both in micro and macro two common terminology : Additively separable. Linear in price or linear in probability. I understand exactly as they sound by looking at the functional form ...
3
votes
2answers
481 views

Does there always exist a consumption bundle at which the indirect utility function is the inverse of the expenditure function?

Two questions: Given $v(\vec{p},m)$ and $e(\vec{p},\bar{U})$, is there only a single point at which these are inverses of each other? Does an inverse always exist for a given price vector $\vec{p}$,...
3
votes
1answer
6k views

Calculate the substitution effect

Utility function $$ U=4{q_1}^{0.5}+q_2 \\ Y=10 $$ $$ p_1=p_2=1 $$ Then $p_1$ rises to 2. I would like to ask how to calculate the substitution effect on the demand for q1? What I have done is ...
3
votes
4answers
4k views

Can someone explain graphically why MRS is invariant under monotonic transformation?

Let $U(x,y)$ be a utility function. Suppose I have an indifference curve for which $U(x,y) = \bar{U}$. Then $dU = 0$ along the curve and I can rearrange to find the MRS. Suppose I have a monotonic ...
2
votes
1answer
662 views

For a given set of consumption bundles, how do we know there are bundles that the consumer is indifferent between?

In my professors lecture notes (it's more like a book), he states four properties of preferences relations: monotonicity transitivity continuity completeness He then goes on to discuss utility ...
1
vote
1answer
72 views

Is the study of the volunteer sector inappropriate for a labour economist?

In the basics of labour economics the driving factor for increase in labour supply (for the workers in a given market) is increase in wages. The volunteer sector consists of general and skilled ...
1
vote
1answer
405 views

Pure exchange economy with free and non-free disposal

Question is as follows: My answers are (I) Let k is constant utility level Then $$k=\sqrt{x_A^1x_A^2}$$ $$k^2/x_A^1=x_A^2$$ The first derivative is negative. So the indifference curve is ...
1
vote
0answers
86 views

Kuhn Tucker optimization problem and game theory [duplicate]

Consider a game with two players, where each player i= 1 ,2 has preferences $u_i$= $s_i^a$$c_i^{1-a}$, where c_i is the consumption and $s_i$ is social interaction. $s_i$ is given by : $s_i$ = $t_i$ + ...
1
vote
1answer
855 views

Utility function used to indicate bliss point

How does one create a utility function to indicate existence of a bliss point? what do the goods marshillian demands look like in such a situation?
0
votes
3answers
183 views

What do interest rates tell us about the state of an economy?

I seem to have a misconception about what interest rates mean. On one hand, they signal how high a government's demand for money is, because if a government is ever in any serious need of money, they ...