课程名称：个体经济学
课程性质：必修
课程范围：ch3ch4(含附录）
开课教师：郑鸿章
开课学院：商学院
开课系级：国贸系
考试日期(年月日)：20190110
考试时限(Mins)：120min
附注：无
试题本文：
每题占20%
一、Suppose you are in charge of a toll bridge that costs essentially nothing
to operate. The demand for bridge crossings Q is given by P=15-1/2Q.
a. Draw the demand curve for bridge crossings.
b. How many people would cross the bridge if there were no toll?
c. What is the loss of consumer surplus associated with a bridge toll of
$5?
d. The toll-bridge operator is considering an increase in the toll to $7.
At this higher price, how many people would cross the bridge? Would the
toll-bridge revenue increase or decrease? What does your answer tell
you about the elasticity of demand?
e. Find the lost consumer surplus associated with the increase in the
price of the toll from $5 to $7.
二、Sharon has the following utility function: U(X,Y)=√X + √Y , where X is
her cinsumption of candy bars, with the price Px=$1, and Y is her
consumption of espressos, with Py=$3.
a. Derive Sharon's demand for cnady bars and expressos.
b. Assume that her income I=$100. How many candy bars and how many
expressos will Sharon consume?
c. What is the marginal utility of income?
三、请以数学推导“边际效用递减”与“边际替代率递减”两者之因果关系；并以之求出
消费组合(X,Y)，两财当其为完全替代与完全互补时之效用无差异曲线。
四、假定Ｘ财价格不变，消费者所得不变，当Ｙ财的价格下降时，请利用图形分析说明
a. Ｙ财为正常财
b. Ｙ财为劣等财但非季芬财
c. Ｙ财为季芬财
等三种情况。
五、请建立“所得-休闲模型”，分别以数学及图形分析说明何以劳动供给曲线会呈现后
弯的形状？