  The Pennsylvania Additive Classification Tool (PACT) is a carceral algorithm
used by the Pennsylvania Department of Corrections in order to determine the
security level for an incarcerated person in the state's prison system. For a
newly incarcerated person it is used in their initial classification. The
initial classification can be overridden both for discretionary and
administrative reasons. An incarcerated person is reclassified annually using a
variant of the PACT and this reclassification can be overridden, too, and for
similar reasons. In this paper, for each of these four processes (the two
classifications and their corresponding overrides), we develop several logistic
models, both binary and multinomial, to replicate these processes with high
accuracy. By examining these models, we both identify which features are most
important in the model and quantify and describe biases that exist in the PACT,
its overrides, and its use in reclassification. Because the details of how the
PACT operates have been redacted from public documents, it is important to know
how it works and what disparate impact it might have on different incarcerated
people.
