Normative economic principles are concerned with how people_make decisions while positive economic principles are concerned with how people_make decisions（）
A. in power; in ordinary life
B. do; should
C. should; do
D. in ordinary life; in power
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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
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
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