Dummy variable omitted because of collinearity stata manual - A Practitioner’s Guide to Cluster-Robust Inference
olinf lets desmat report which variables are dropped because of collinearity. the dummy variable for of the variable. The parameter for ref is omitted
. . dummy variable for 1991 would have introduced exact collinearity unless the intercept was omitted. Exact collinearity because the sum of the dummy
Regression with Stata Chapter 2 – Regression Diagnostics. long as it is a legal Stata variable because the high degree of collinearity caused the
ummy A Stata Command to Create Dummy Variables and Interactions from Categorical Variables requirements of a variable name in Stata,
/8/2018 to prevent the dummy variable trap.
A Practitioner’s Guide to Cluster-Robust Inference the e ect of a policy variable, for simplicity and because this is the most commonly-used estimation