give all

Problem 1. Demand Bengt's utility function is U(x1, x2)= x1 + ln x2 x1 - stamps x2 - beer Bengts budget p1 x1 + p2 x2 = m p1 - price of stamps p2 - price of beer m - Bengt's budget a) What is Bengt's demand for beer and stamps? b) Is it true that Bengt would spend every krona in additional income on stamps? c) What happens to demand when Bengt's income changes (i.e. find the income elasticity)? d) What happens to demand when p1 and p2 increase (i.e. find the price elasticities)? Problem 2. Demand Jan has fallen on hard times. His income per week is 400 kr, spending 200 kr on food and 200 kr on all other goods. However, he is also receiving a social allowance in the form of 10 food stamps per week. The coupons can be exchanged for 10 kr worth of food, and he only has to pay 5 kr for such coupons. Show the budget line with and without the food stamps. If Jan has homothetic preferences, how much more food will he buy when he receives the food stamps? Problem 3. Demand Find the demand functions for the individuals below, the budget constraint is pxx+pyy=m Bill: U(x1,x2) = x2 y3 Buster: U(x, y)=x2/5y3/5 Ben: U(x, y) = (x+1)2 (y+2)3 Barbara: U(x1,x2) =3x +2y Beth: U(x, y)=min{x , y} Problem 4. Demand Birgitta spends 150 SEK per month on coffee and buns at the cafeteria. A cup of coffee costs 15 SEK and a bun costs 10 SEK. a) Write the equation for Birgitta's cafeteria budget constraint and draw it in a diagram. b) Assume that Birgitta never drinks coffee without eating one bun, and never eats buns without drinking coffee. How much of each will she consume? Draw some of her indifference curves. c) What do we call goods that are always consumed in the same proportion? Problem 1 Slutsky equation Tomas is trying to figure out how to supplement the study allowances of 500 kr a week. He is considering a part-time job at a gas station. The wage is 50 kr per hour. His utility function is U(C, L) = C*L where C is his consumption measured in SEK and L his leisure measured in hours. The amount of leisure time that he has left after allowing for necessary activities is 50 hours a week. a. What is the monetary value of Tomas' endowment? b. Draw Tomas' budget set (horizontal axis: leisure and vertical axis: consumption). c. Set up the maximisation problem and decide optimal consumption and leisure. d. Let Y = study allowance and T = total amount of leisure time. Express his demand for consumption as a function of study allowance and wage. e. Express his supply function for labour as a function of study allowance and wage. f. How many hours would Tomas work if he did not receive any study allowance? Problem 2 Slutsky equation Assume that the function U(x, y) = x0.3y0.5 is the utility function of a person who consumes two goods in quantities x and y, respectively. The price of x is px = 5 and the price of y is py = 8 This persons income is m = 160. a) Find the optimal consumption choice of this person. b) Verify that at the optimum that you found the marginal rate of substitution equals the price ratio. Explain in terms of economic theory why this should be the case! c) Assume that the price of x falls to px

i. Draw the old and the new budget constraints in a diagram. (Indicate at what values they intersect the axes). ii. Calculate the persons demand for x and y at the new price. iii. Calculate the compensated income, m. iv. Decompose the change in demand for good x into a substitution and an income effect. Problem 1. Consumer's surplus Mattias has quasilinear preferences and his demand function for books is B = 15 - 0.5p. a) Write the inverse demand function b) Mattias is currently consuming 10 books at a price of 10 kr. How much money would he be willing to pay to have this amount, rather than no books at all? What is his level of consumer's surplus? Problem 2. Consumer's surplus Suppose Birgitta has the utility function U = x10.1 x20.9. She has an income of 100 and P1= 1 and P2= 1. Calculate compensating and equivalent variation when the price of x1 increases to 2. Also, try to estimate the change in consumer's surplus measured by the area below the demand function. Problem 3. Consumer's surplus Explain the concept of "consumer surplus" in words and illustrate by a diagram. Problem 4. Consumer's surplus The inverse demand curve (the demand curve but with p instead of q on the left hand side) is given by p(q)=100-10q. The consumer consumes five units of the good (q). a) How much money would you have to pay to compensate her for reducing her consumption to zero? (The consumer is not paying anything for the goods.) b) Suppose now that the consumer is buying the goods at a price of 50 per unit. If you now require her to reduce her purchases to zero, how much does she need to get compensated? Hint: The number you will find is the net consumer's surplus. Problem 5. Consumer's surplus New housing is planned in Karlstad but the location where it is to be built is used as a popular recreation area for people in neighbouring parts of the city. In order to decide whether to build or not, the city authorities want to make a survey to measure the decrease in welfare due the loss of this recreation area. They are told by an economist that two measures are possible, compensating variation (CV) and equivalent variation (EV). a) How should they formulate the question if they want to measure the compensating variation? b) How should they phrase it if they want to measure the equivalent variation? Problem 1. Market demand Linus has a demand function q = 10 - 2p a. What is the price elasticity of demand when the price is 3? b. At what price is the elasticity of demand equal to -1? c. Suppose that his demand function takes the general form q = a - bp. Write down an algebraic expression for his elasticity of demand at an arbitrary price p. Problem 2. Market demand The demand function is q(p) = (p+1)-2 a. What is the price elasticity of demand? b. At what price is the price elasticity of demand equal to minus one? c. Write an expression for total revenue as a function of the price. d. Answer a-c when the demand function takes the more general form q(p) = (p+a)b where a > 0 and b < -1. Problem 3. Market demand Find the price elasticity of demand for the following demand functions. a) D(p)=30-6p b) D(p)=60-p c) D(p)=a-bp d) D(p)=40p-2 e) D(p)=Ap-b f) D(p)=(p+3)-2 Problem 1. Equilibrium Suppose we have the following demand and supply equations D(p) = 200 - p S(p) = 150 + p a. What is the equilibrium price and quantity? b. The government decides to restrict the industry to selling only 160 units by imposing a maximum price and rationing the good. What maximum price should the government impose? c. The government doesn't want the firms in the industry to receive more than the minimum price that it would take to have them supply 160 units of the good. Therefore, they issue 160 ration coupons. If the ration coupons were freely bought and sold on the open market, what would be the equilibrium price of these coupons? d. Calculate the dead-weight loss from restricting the supply of the goods. Will the dead-weight loss increase or decrease if the government would not allow the coupons to be sold on the open market? Problem 2. Equilibrium The demand curve is qD = 100 - 5p and the supply curve is qS = 5p. a. A quantity tax of 2 kr per unit is placed on the good. Calculate the dead-weight loss of the tax. b. A value (ad valorem) tax of 20 % is placed on the good. Calculate the dead-weight loss of the tax. Problem 3. Equilibrium Assume that both demand and supply for a good are linear functions of its price: D(p) = a + bp, a > 0, b < 0 S(p) = c + dp, c < 0, d> 0 a) Draw curves that fit this description in a diagram. b) Assume that a tax t per unit has to be paid by the consumer. Show the effects on demand, supply, equilibrium price, quantity consumed and consumer and producer welfare in your diagram. c) Assume instead that an equally large tax has to be paid by the producer. What are the effects now on demand, supply, equilibrium price, quantity consumed and consumer and producer welfare. (Use a diagram to illustrate.) Problem 1. Intertemporal choice Suppose that a consumer has an endowment of 200.000 kr each period (period 1 and 2). He can borrow money at an interest rate of 200%, and he can lend money at a rate of 0%. a. Illustrate his budget set. b. The consumer is offered an investment that will change his endowment to m1 = 300.000 and m2 = 150.000. Would the consumer be better or worse off, or can't you tell? c. If he is offered m1 = 150.000 and m2 = 300.000, is he better or worse off? Problem 2. Intertemporal choice Mainy Landin has an income of 200.000 kr this year and she expects an income of 110.000 kr next year. She can borrow and lend money at an interest rate of 10%. Consumption goods cost 1 kr and there is no inflation. a. What is the present value of Mainy's endowment? b. What is the future value of Mainy's endowment? c. Suppose that Mainy has the utility function U = c1c2. Write down Mainy's marginal rate of substitution. d. Set this slope equal to the slope of the budget line and solve for the consumption in period 1 and 2. Will she borrow or save in the first period. e. = d, but the interest rate is 20%. Will Mainy be better or worse off? Problem 1. Uncertainty Jonas Thern maximises expected utility: U(1, 2,c1,c2) = 1c1+ 2c2 Jonas's friend Stefan Schwarz has offered to bet him 10.000 kr on the outcome of the toss of a coin. If the coin comes up head, Jonas must pay Stefan 10.000 kr, and if the coin comes up tails, Stefan must pay Jonas 10.000 kr. If Jonas doesn't accept the bet, he will have 100.000 kr with certainty. Let Event 1 be "coin comes up heads". a. What is Jonas's utility if he accepts the bet and if he decides not to bet? Does Jonas take the bet? b. Answer the question in a, if the bet is 100.000 kr. c. Answer the question if Jonas must pay Stefan 100.000 kr if he coin comes up head, but if the coin comes up tails Stefan must pay Jonas 500.000 kr. d. Klas Ingesson would also like to gamble with Jonas. He is very intelligent and realises the nature of Jonas' preferences. He offers him a bet that Jonas will take. Klas says: "If you loose you will give me 10.000 kr. If you win, I will give you ........? Problem 2. Uncertainty Gabriel likes to gamble and his preferences are represented by the expected utility function U = 1c12 + 2c22 Gabriel has not worked out very well, he only have 1.000 kr. Thomas shuffled a deck of cards and offered to bet Gabriel 200 kr that he would not cut a spade from the deck. a. Show that Gabriel refuses the bet. b. Would Gabriel accept the bet if they would bet 1.000 kr instead of 200 kr? c. Sketch one of Gabriel's indifference curves (let Event 2 be the event that a card drawn from a fair deck of cards is a spade) d. On the same graph, sketch the indifference curve when the gamble is that he would not cut a black card from the deck. Problem 3. Uncertainty Consider an individual with an income of 100. She has the option of participating in a lottery where she can win 30 with a probability of 0.5, and loose 30 with a probability of 0.5. Would she participate if she is risk averse? What id she is a risk lover? Explain Answers to the problems Problem 1. Demand a) Given prices, p1 and p2, find the quantities x1 and x2 which maximise Bengt's utility! Necessary condition: MU1= 1 MU2=1/x2 MRS = x2 Therefore the optimum occurs when Money left to buy x1 for: if m>p1 b) Yes, if m>p1 he won't buy any more beer when m increases. c)-d) 2 1 2 p Problem 2. Demand y = 400 10 food stamps per week, price 5 kr. Can be exchanged for 10 kr worth of food. Old budget line: max 400 other and 400 food. New budget line: max 400 other and 450 food, kink at 100 food and 350 other. Homothetic preferences: The income expansion path is a straight line through origin. Since Jan spent half his income on food, he will continue doing so. His income increases by 50 Problem 4. Demand C denotes the number of cups of coffee and B the number of buns: a) 15C+ 10B = 150. The budget line intersects the "coffee-axis" at C = 10 and the "bun-axis" at B = 15. b) 6 of each. Her indifference curves are