Homework 3

Paving Albany’s Streets

 

A.  The City of Albany paves its own streets using labor, trucks (although several different types of equipment are employed, in our example let’s generically think of them as trucks), and storage facilities.  In the short run the number and size of storage sites is fixed.  However, the City does vary the amount of labor and the number of trucks it employs.  The following table indicates the linear length of streets that can be paved (in yards) with various combinations of the two inputs.  For example, 50 hours of labor and 2 trucks yield 32 yards of road.

 

 

Number of Trucks

Hours of Labor

1

2

3

4

 

 

 

 

 

50

12

32

47

57

100

26

46

61

71

150

38

58

73

83

200

48

68

83

92

250

57

77

92

102

300

65

85

100

110

350

72

92

107

117

400

78

98

113

123

450

83

103

118

128

500

87

107

122

132

550

90

110

125

135

600

92

112

127

137

 

                1.   Calculate the marginal product for labor (use 50 hours of labor as one unit) when the number of trucks is fixed at 1.

                2.  If the rental rate of trucks is $1500 per day and the wage rate of workers is $20 per hour, what is the

                                cheapest way to pave 92 yards of street in a day?

                3. Would it ever be the case that the City would find it cheaper to rent a different number of trucks (give an example)?

               

B. The following total cost data is calculated assuming that Albany has two storage sites that cost $400 each to rent per day .   Answer the questions following the table.

 

Output   Total       Average                 Average                 Marginal                  Total                      Marginal               Profit

(yards)   Cost        Total                      Variable                   Cost                      Revenue                   Revenue

                                 Cost                       Cost

  0            800

 20           4000

 40           6000

 60           8200

 80        10,600

100       13,200

120       16,000

140       19,000

160       22,200

180       25,600

200       29,200

 

1. Calculate the average total cost, average variable cost, and marginal cost for street paving per day.

2. The going rate for paving by private sector firms is $155 per yard.  If the above cost data were for a private sector firm calculate total revenue, marginal revenue, and profit (per yard of paving).

3. Graph (at least in a rough way) average total cost, average variable cost, marginal cost, and marginal revenue (all on the same graph).