The correlation of a dichotomous variable and a continuous (normal?) variable is closely related to the t-test. If you look at the p-value it is exactly the same as the p-value from a t-test for the continuous variable using the dichotomous variable as the 'by' variable. It's meaning depends on whether the continuous variable is close to normal
Tony
Peter A. Lachenbruch
Department of Public Health
Oregon State University
Corvallis, OR 97330
Phone: 541-737-3832
FAX: 541-737-4001
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Christian Weiß
Sent: Monday, September 21, 2009 7:45 AM
To: statalist
Subject: st: Correlation of Dummy and Metric Variables?
Dear Statalist,
although it's not a particularly Stata specific question , I am hoping
to get advise on the following (basic?) question:
I am using the following command to get a correlation matrix
quietly estpost correlate `vars', matrix
esttab using correlations.csv, not unstack compress noobs star(* 0.10
** 0.05 *** 0.01) long b(%9.2f) replace
`vars' containts a battery of mostly metric variables. Besides the
metric variables, there is also three dummy variables.
I am wondering now if the reported (relatively high) correlation
coefficients among the dummy variables and between some of the metric
variables and the dummy variables are actually meaningful. How to
interpret them / which correlation test to use?
Thank's a lot,
Christian
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