In: Economics
microeconomics
Bob goes to the supermarket to buy milk and cereal. He has $20 to spend. A consumption bundle consists of a quantity of milk, x (liters), and a quantity of cereal, y (grams). For all of the following questions you can assume that the consumption set is R2+. This means that milk and cereal can be consumed in any non-negative quantity.
(a) The price of milk at the supermarket is px = 4$/liter. The price of cereal is 0.2cents/gram. Draw Bob’s budget set. What is the slope of the budget line?
(b) Bob notices that the supermarket has a special coupon. A coupon states: “Buy 1 liter of milk and get 1 box of cereal for free”. A box of cereal has 2000 grams of cereal in it. Each shopper is limited to one coupon. Draw Bob’s budget set with 1 coupon. (Hint: Be careful with units again).
(c) Due to popular demand, the supermarket extends its special of- fer. Each customer is now allowed to use 2 coupons. Draw Bob’s budget set with 2 coupons.
(d) Finally, the supermarket decides to allow each customer to use an unlimited number of coupons. Draw Bob’s budget set if he has an unlimited number of coupons.
(e) Bob is smart and his friends are lazy. Bob’s friends know the prices at the supermarket but they do not know about the coupons. Bob offers to buy their cereal for them, and his friends agree to pay him exactly what they would have to pay for cereal at the supermarket, i.e., they will pay him 0.2cents/gram of cereal. Suppose that Bob’s friends are willing to buy an unlimited amount of cereal at this price. Bob’s budget set now consists of all consumption bundles he can afford given his wealth of $20, the prices at which he can buy milk and cereal at the supermarket, the unlimited number of coupons, and the price at which he can sell cereal to his friends. Draw the budget set.
The solution to this question is given in the pictures below. The budget line gives the combinations of the two goods that can be purchased with given income or endowment.