I need to run a regression with a variable that has 20 different categories. I figured i could make a dummy with 20 different columns with 1 and 0. However when im running my regression i can only use 16 X variables. Does anyone know how i can fix this?

​I need to run a regression with a variable that has 20 different categories. I figured i could make a dummy with 20 different columns with 1 and 0. However when im running my regression i can only use 16 X variables. Does anyone know how i can fix this?  Read More

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