Use esttab to generate summary statistics by group with columns for mean difference and significance
I would like to use esttab (ssc install estout) to generate summary statistics by group with columns for the mean difference and significance. It is easy enough to generate these as two separate tables with estpost, summarize, and ttest, and combine manually, but I would like to automate the whole process.
The following code generates the two components of the desired table.
sysuse auto, clear
* summary statistics by group
eststo clear
by foreign: eststo: quietly estpost summarize ///
price mpg weight headroom trunk
esttab, cells("mean sd") label nodepvar
* difference in means
eststo: estpost ttest price mpg weight headroom trunk, ///
by(foreign) unequal
esttab ., wide label
And I can print the two tables and cut-an-paste into one table.
* can generate similar tables and append horizontally
esttab, cells("mean sd") label
esttab, wide label
* manual, cut-and-paste solution
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(1) (2) (3)
mean sd mean sd
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Price 6072.423 3097.104 6384.682 2621.915 -312.3 (-0.44)
Mileage (mpg) 19.82692 4.743297 24.77273 6.611187 -4.946** (-3.18)
Weight (lbs.) 3317.115 695.3637 2315.909 433.0035 1001.2*** (7.50)
Headroom (in.) 3.153846 .9157578 2.613636 .4862837 0.540** (3.30)
Trunk space (.. ft.) 14.75 4.306288 11.40909 3.216906 3.341*** (3.67)
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Observations 52 22 74
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t statistics in parentheses
* p<0.05, ** p<0.01, *** p<0.001
It seems that I should be able to get the desired table with one esttab call and without cutting-and-pasting, but I can't figure it out. Is there a way to generate the desired table without manually cutting-and-pasting?
I would prefer to output a LaTeX table, but anything that eliminates the cutting-and-pasting is a big step, even passing through a delimited text file.
Answer
If you still want to use esttab, you can play around using cells and pattern. The table in the original post can be replicated with the following code:
sysuse auto, clear
eststo domestic: quietly estpost summarize ///
price mpg weight headroom trunk if foreign == 0
eststo foreign: quietly estpost summarize ///
price mpg weight headroom trunk if foreign == 1
eststo diff: quietly estpost ttest ///
price mpg weight headroom trunk, by(foreign) unequal
esttab domestic foreign diff, ///
cells("mean(pattern(1 1 0) fmt(2)) sd(pattern(1 1 0)) b(star pattern(0 0 1) fmt(2)) t(pattern(0 0 1) par fmt(2))") ///
label
which yields
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(1) (2) (3)
mean sd mean sd b t
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Price 6072.42 3097.10 6384.68 2621.92 -312.26 (-0.44)
Mileage (mpg) 19.83 4.74 24.77 6.61 -4.95** (-3.18)
Weight (lbs.) 3317.12 695.36 2315.91 433.00 1001.21*** (7.50)
Headroom (in.) 3.15 0.92 2.61 0.49 0.54** (3.30)
Trunk space (.. ft.) 14.75 4.31 11.41 3.22 3.34*** (3.67)
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Observations 52 22 74
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