Statistical Analysis Stack Exchange
Statistical Analysis Stack Exchange

Questions tagged [dummy-variable-trap]

If you use a separate dummy code for every level of a categorical predictor and there is an intercept in the model, this leads to perfect multicollinearity. This is known as the "dummy variable trap".

See Qualitative variable coding in regression leads to “singularities” for an explanation.

5 questions
5
votes
1 answer

Clear explanation of dummy variable trap

I have a confusion in multiple regression about dummy variable trap, so far I had seen tutorials explaining about dummy variable trap and multicollinearity but I'm unable to understand it fully.
Sahil Silare
  • 163
  • 1
  • 5
5
votes
2 answers

Dummy variable trap?

1) Does including both part time and temporary work cause a dummy variable trap? If not, can we exclude temporary work as an explanatory variable to explain wages in a country as the nature of work is inconsistent, hence its power of predictability…
Sarin
  • 71
  • 1
  • 1
  • 4
3
votes
1 answer

Which ML Algorithms are affected by dummy variable trap?

My understanding is that regression models are affected by the dummy variable trap. What about other machine learning algorithms e.g. linear svm, logistic regression? Also, if an algorithm is not affected , is it bad practise to remove a dimension…
Stamatis Tiniakos
  • 145
  • 5
3
votes
1 answer

Dummy variable trap in survival models

I am familiar with the dummy variable trap in normal OLS, in which we should include one less dummy variable than the total of categories to avoid the problem of multicollinearity. However, I was wondering if it is also the case in duration models.…
Not Fisher
  • 43
  • 3
-1
votes
1 answer

Dummy Variable Trap in Stata

So basically I am using the wine.dta file and have a range of dummy variables for 6 regions. I have excluded 1 of the regions (regressing on 5 of the dummy variables) but for some reason Stata says there is still a collinearity problem and only…
Boa
  • 1
  • 1