Question 1 · Calculation & Diagrammatic Application
5 marks1 A country can produce combinations of machinery and food, as shown on its production possibility frontier (PPF):
Point | Machinery (units) | Food (units)
A | 0 | 100
B | 20 | 90
C | 40 | 60
(a) Calculate the opportunity cost, in units of food given up, of increasing machinery production from 20 to 40 units (moving from point B to point C). [2]
(b) A point D represents the combination (30 machinery, 60 food). Explain, using the concept of the PPF, what point D represents. [3]
Point | Machinery (units) | Food (units)
A | 0 | 100
B | 20 | 90
C | 40 | 60
(a) Calculate the opportunity cost, in units of food given up, of increasing machinery production from 20 to 40 units (moving from point B to point C). [2]
(b) A point D represents the combination (30 machinery, 60 food). Explain, using the concept of the PPF, what point D represents. [3]
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Worked solution
(a) At B, food output is 90; at C, food output is 60. The opportunity cost of the extra 20 units of machinery (from 20 to 40) is the fall in food output: \( 90 - 60 = 30 \) units of food.
(b) Following the straight line between B (20, 90) and C (40, 60), the maximum food output attainable when producing 30 units of machinery is 75 units (halfway between 90 and 60). Since point D produces only 60 units of food at 30 units of machinery, which is below the frontier, D represents a combination of output that is attainable but does not use all of the economy's resources fully or efficiently (for example, due to unemployed resources); the economy could produce more of both goods by moving out to the PPF itself.
(b) Following the straight line between B (20, 90) and C (40, 60), the maximum food output attainable when producing 30 units of machinery is 75 units (halfway between 90 and 60). Since point D produces only 60 units of food at 30 units of machinery, which is below the frontier, D represents a combination of output that is attainable but does not use all of the economy's resources fully or efficiently (for example, due to unemployed resources); the economy could produce more of both goods by moving out to the PPF itself.
Marking scheme
(a) [1] for correct method (food at B minus food at C); [1] for correct answer of 30 units of food.
(b) [1] for identifying that D lies inside/within the PPF; [1] for explaining this means resources are not fully/efficiently used (e.g. unemployment of resources); [1] for explaining that more of both goods could be produced by moving towards the frontier.
(b) [1] for identifying that D lies inside/within the PPF; [1] for explaining this means resources are not fully/efficiently used (e.g. unemployment of resources); [1] for explaining that more of both goods could be produced by moving towards the frontier.