stata如何estate common命令怎么解读

stata如何estate common命令怎么解读

stata如何estate common命令怎么解读
一般用ttest.
. sysuse auto

. ttest mpg==20
. webuse fuel3
. ttest mpg, by(treated)
. webuse fuel
. ttest mpg1==mpg2
// (immediate form; n=24, m=62.6, sd=15.8; test m=75)
. ttesti 24 62.6 15.8 75

test有不同的用法，下面是一些例子：
Examples after single-equation estimation
Setup
. webuse census3
. regress brate medage medagesq i.region
Test coefficient on 3.region is 0
. test 3.region=0
Shorthand for the previous test command
. test 3.region
Test coefficient on 2.region=coefficient on 4.region
. test 2.region=4.region

Stata will perform the algebra, and then do the test
. test
2*(2.region-3*(3.region-4.region))=3.region+2.region+6*(4.region-3.regio
> n)

Test that coefficients on 2.region and 3.region are jointly equal to 0
. test (2.region=0) (3.region=0)
The following two commands are equivalent to the previous test command
. test 2.region = 0
. test 3.region = 0, accumulate
Test that the coefficients on 2.region, 3.region, and 4.region are all 0;
testparm understands a varlist
. testparm i(2/4).region
In the above example, you may substitute any single-equation estimation command
(such as clogit, logistic, logit, and ologit) for regress.
Examples after multiple-equation estimation commands
Setup
. sysuse auto
. sureg (price foreign mpg displ) (weight foreign length)

Test significance of foreign in the price equation
. test [price]foreign

Test that foreign is jointly 0 in both equations
. test [price]foreign [weight]foreign

Shorthand for the previous test command
. test foreign

我不会~~~但还是要微笑~~~：）