My response variable $y_i$ denotes the number of articles produced by journalist $i$ in the last two years. It is a count variable with fixed exposure hence why I chose to use Poisson regression.
I have a dataset containing the number of articles produced by numerous different journalists and I also have values of other variables (my predictor variables).
I have calculated the sample mean and sample variance of the variable $y$, and the sample variance is nearly double (over-dispersion). Is this a good enough reason for me to use negative Binomial regression? Should I consider anything else? The deviance of the model also drops by a noticeable amount when I use NB over Poisson.
This is my first time considering using a negative Binomial regression so I apologise if the question is very basic.