"economics"exercise:Variable
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Questions 1:
Six companies in an industry have the following market shares:
If Companies D and F merge into a new Company, G, the industry’s threecompany concentration ratio would be closest to:
A 、72%.
B、 74%.
C、 71%.
Questions 2:
In the short run, a firm operating in a perfectly competitive market will most likely avoid shutdown if it is able to earn sufficient revenue to cover which of the following costs?
A 、Fixed
B 、Marginal
C 、Variable
B is correct. The concentration ratio for the top three companies would be 74%: A (30%) + B (25%) + G (12% + 7%).
A is incorrect. 72% is the concentration ratio of the top three companies if the two smallest merge: A (30%) + B (25%) + [E (10%) + F (7%)].
C is incorrect. 71% is the concentration ratio of the original top three companies: A (30%) + B (25%) + C (16%).
C is correct. Shutdown is defined as a situation in which the firm stops production but still confronts the payment of fixed costs in the short run. In the short run, a business can operate at a loss as long as it covers its variable costs even though it is not earning sufficient revenue to cover fixed costs. If variable costs cannot be covered in the short run , the firm will shut down operations and simply absorb the unavoidable fixed costs.
B is incorrect. Marginal cost is the incremental cost of producing one more unit and can be calculated as either (Δ total cost/Δ quantity) or (Δ total variable cost/Δ quantity).
A is incorrect. In the short run, a business can operate at a loss as long as it covers variable costs even though it is not earning sufficient revenue to cover fixed costs.
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