The cost-benefit model used by economists is（）
A. useful because most people follow it most of the time
B. useful because everyone follows it all of the time
C. unrealistic because it is too detailed and specific to apply to most situations
D. unrealistic because everyone can think of times when he or she violated the principle
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Economists recognize that because people have limited resources（）
A. our future is bleak
B. they will never be happy
C. they have to make trade-offs
D. government intervention is necessary
The Incentive Principle states that a person（）
A. is more likely to take an action if its cost increases
B. should take an action if its benefit increases
C. should take an action if its cost increases
D. is more likely to take an action if its benefit increases
Jack has a ticket to see Bo Bice for which he paid $30 yesterday. He takes an unpaid day off from work to get ready for the concert. When he arrives at the concert, five different people offer him $70
A. $70 plus his forgone earnings
B. $70
C. $40
D. $30 plus his forgone earnings
You are trying to decide whether to purchase the latest Harry Potter book online or borrow it from the library. There is no charge for borrowing a book from the library, but going to the library takes
A. buy the book online because it takes less time
B. borrow the book from the library because you can get it from the library for free
C. borrow the book from the library if the cost of doing so （in terms of the extra time it takes） is greater than $13
D. borrow the book from the library if the cost of doing so （in terms of the extra time it takes） is less than $13
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