a*****b
发帖数: 2789 | 1 Hi all,
I have a question about reading multiple data files by SPSS.
For example, I have more than thousand files with the name:
a.svy.txt
b.svy.txt
.
.
.
xxx.svy.txt
How to read all of them but not use
add files file="a.svy.txt"
/file="b.svy.txt"
...
can I read all of them one time like
data list file='*.svy.txt' or some other technique?
Thanks a lot! |
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j*****i
发帖数: 47 | 2 请教一下:如何用Stata和SAS从weighted data里面随机抽取几个样本？
数据：weighted US census data (weight: perwt，即person weight).
我想在这个数据中随机有放回地抽取n个人。
简化一下，就是，比如我们有一个data set, 里面只有两个变量，age and perwt。每
一个observation,代表了那个年龄组里的所有的人。
现在，我想随机从这个数据中抽取10个人，不是10个observation.
请问，Stata和SAS的相关命令是什么？
Stata中，有一个类似的命令bsample 10。但是没有相关的option可以设定原数据中的
weight,倒是有一个option是用来设定输出数据中的weight.
我也想过用svyset，但是我试了
svyset [iweight=perwt]
svy: bsample 10
显示的是：
svyset [iweight=perwt]
iweight: perwt
VCE: linearized
Single unit: mis... 阅读全帖 |
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f*******r
发帖数: 257 | 3 Check out "svy: heckman". Frankly, I don't see your algorithm generates
consistent estimator. svy: heckman is build-in Stata command, should be
consistent. |
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H****g
发帖数: 2273 | 4 这个可以做的，很多command都支持，不过麻烦的是不同的command要求的weight有时不
太一样。
也可以试试svy，楼主自己help svy试试，这个也许方便一点。 |
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C*****1
发帖数: 185 | 5 Thanks for responding.
I checked svy: heckman, but it can not be applied to two-step procedure. |
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f*******r
发帖数: 257 | 6 I think there is a misconception. You don't need the Heckman two-step
estimator per se. Heckman model usually refers to the model which adjust
for selection bias or selectivity. There is so called Heckman two-step
estimator which is one way to estimate the model, but not the only one. In
fact, maximum-likelihood estimator is more efficient. I have not used it;
but I think svy: heckman is a ML estimator which allows for sampling weight.
It does not do Heckman's two-step estimator for a rea |
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