Problem Set 1
(due Tuesday October 20 15:00)
EC 2010

1.（5分）从Blackboard下载数据集SIPP durations.dta并将其保存在您的数据中

（a）显示数据集内容的摘要。多少个变量和几个

（b）显示变量avgwba的详细摘要统计信息。 75％的百分位数是多少

（c）计算dur与失业救济金水平之间的相关性（avgwba）。什么是
dur和avgwba之间的相关性？现在生成一个新的变量ubenin100

（d）计算并显示变量dur，avgwba和annwg的相关矩阵。什么

1个
（e）如果失业持续时间（dur）产生一个变量longtermu，其值为1

（f）显示每个长期类别的annwg的摘要统计信息。长期失业者的失业前工资是低于还是高于短期失业者？长期失业者的工资变化是否更大？
（g）创建一个新变量annwg2，它是变量annwg的平方。绘制

（h）显示失业时间和失业救济金水平的直方图。
（i）根据变量avgwba绘制变量dur。在轴上放置标题，然后在

（j）产生新的变量havgwba，如果失业救济金高于1，则其值为1

（havgwba = 0）。确保标记轴并将标题放在图形上。是个

2.（2分）考虑一下讲座中讨论的Ebert和Roper的修改示例。让

EB = 4 EB = 2 EB = 0总计
RO = 4 0.4 0.06 0.01 0.47
RO = 2 0.07 0.08 0.1 0.25
RO = 0 0.08 0.05 0.15 0.28

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（a）（1分）考虑到埃伯特（Ebert）投票为康（在其他情况下，

（b）（1分）定义以下随机变量：
Y =




ii。计算E（Y）。
3. (3 points) Many auto insurance companies in the US advertise themselves by stating that
people who switched to them saved a lot of money. One of them is Geico who says that
you can save even \$500 if you switch (they are also famous for their commercials, here is
one of my favourites. Let’s see how that
works. Suppose that the population consists of 6 people: Arek, Irek, Darek, Marek, Jarek,
Mirek. They choose their auto insurance and you see their yearly premiums:
Geico Other company
Arek \$800
Irek \$1000
Darek \$500
Marek \$680
Jarek \$600
Mirek \$ 900
(for example, Arek has chosen Geico and is paying \$800 a year).
Let Insi denote the random variable indicating the chosen company with:
Insi =



1 Geico
0 other company
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and P RMi1 denote the premium paid by individual i if he is with Geico and P RMi0 the
premium if he is with some other company.
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