If Pareto efficiency has been achieved A) there are no ...

[bobbie]

If Pareto efficiency has been achieved
 
  A) there are no additional Pareto improvements that can be made.
  B) surplus is maximized.
  C) economic efficiency is also achieved.
  D) All of the above.

Question 2

Suppose that a perfectly competitive industry is in long-run equilibrium, and demand increases. Explain the short- and long-run effects on the firm and the industry.
 
  What will be an ideal response?

[ally]

Answer to Question 1

D

Answer to Question 2

Short run: An increase in demand raises equilibrium price and quantity. Existing firms produce more (because the higher price means that MR=MC at a higher quantity) and earn positive economic profits.

Long run: Positive profits attract new firms into the industry. The increase in supply reduces price and further increases quantity. Firms continue to enter until economic profits return to zero, and there is no further incentive for entry.

[bobbie]

Excellent

[strudel15]

Gracias!