Econ 302: Practice Questions 4


Question 1: Solve Question 5.2 in the workbook.

Question 2: Solve Question 5.3 in the workbook.

Question 3: Assume that there are two goods and that a consumers chooses x1=2 and x2=4 (as optimal consumption choice). The consumer's income is m. Let p1=3 and p2=2.

  • Given this information, can you determine the MRS? If your answer is yes, what is the MRS?
  • Does you answer change if the optimal consumption choice is x1=0 and x2=6.

Question 4: Assume the preferences of a consumer are given by u(x1,x2)=x1+4x2.

  • For what price ratio(s) p1/p2 can one get an interior optimum?
  • For what price ratio(s) do you definitely get a boundary optimum?
Question 5: Assume the utility function of a consumer is given by u(x1,x2)=min{x1,x2}.
  • Consider the Budget set from question 3 of the second Problem Set in the review section. Find the optimal consumption choice (you can do it graphically. To find the budget set, click on the above link to get to the problem set, and then click on the question to get to the solution).
  • Same as above except use the utility function u(x1,x2)=min{50x1,x2} and the budget set from question 4.
Question 6: A utility function is given by u(x1,x2) = log(x1+x2)+x1. The resulting MRS=-(x1+x2+1). Assume prices are p1=2, p2=1 (in the following you will get boundary optima (follow this link for some hints!)).
  • Find the optimal choice for m=1.5.
  • Find the optimal choice for m=2.
  • Find the optimal choice for m=3.
  • Does the demand for good 2 increase or decrease as a consequence of the increase of income.

Question 7: In a particular country low income households are supported via a quantity subsidy s on electricity. That is, households who qualify for the program pay a price of p-s per unit of electricity (where p is the regular price). An economist who advises the government argues that this program should be reformed. Specifically, the economist argues the government should provide free electricity to low income households up the a certain amount. Any amount in excess is charged at the regular rate p. The economics argues that if the government spends the same amount of money in this alternative program then the following would be the case.

  • The low income households will be better off.
  • Less electricity will be used. A reduction of the demand for electricity would be especially desirable as the country often faces brownouts.
Demonstrate by means of a graph that the economist is right (assuming that preferences over electricity (good 1) and all other goods (good 2) are convex and monotonic).

Hint: This question combines several different issues discussed in class. First graph the budget lines without any program and with the existing program. Graph an optimal consumption choice. Then determine the budget line for the alternative program.


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