## What about cases where a significant number of observations have a count of 0 (in the context of Poisson Regression)?

In many data generation processes for count data, it is possible that a lot of observations will have a count of zero.

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The poisson distribution is specified by one parameter lambda that represents both the mean and variance of the distribution.

Poisson regression uses the following cost function:

Poisson regression is used where target variable is measured in counts.