I am trying to work with Poisson regression. I came across this video which is very helpful - https://www.youtube.com/watch?v=HntUY8SsYZg. In the video one of parameters (Race) is categorical and treated vide factor() in R.
Ideally the model should show coefficient of every parameter - Race, Income and GPA. But for the categorical variable Race - it shows coefficient for value of categorical variable. [Video at 09:18]
CO 2.5 % 97.5 %
(Intercept) 0.003004161 0.0007308336 0.01167968
Race2 2.811686825 1.5523542481 5.62637686
Race3 1.310301471 0.5854852933 2.98624050
Income 1.066367468 1.0494809143 1.08382221
GPA 1.129708044 0.9120963633 1.40195401
Can someone explain this ? why is every value of categorical variable having a different coefficient ?