By Christoph Heitz (ZHAW)
translated from original German language version published at Inside IT
Can a prisoner be released early, or released on
bail? A judge who decides this should also consider the risk of
recidivism of the person to be released. Wouldn’t it be an
advantage to be able to assess this risk objectively and reliably?
This was the idea behind the COMPAS system developed by the US
company Northpoint.
The
system makes an individual prediction of the chance of recidivism for
imprisoned offenders, based on a wide range of personal data. The
result is a risk score between 1 and 10, where 10 corresponds to a
very high risk of recidivism. This system has been used for many
years in various U.S. states to support decision making of judges –
more than one million prisoners have already been evaluated using
COMPAS. The advantages are obvious: the system produces an objective
risk prediction that has been developed and validated on the basis of
thousands of cases.
In
May 2016, however, the journalists’ association ProPublica published
the results of research suggesting that this software systematically
discriminates against black people and overestimates their risk
(Angwin et al. 2016): 45 percent of black offenders who did not
reoffend after their release were identified as high-risk. In the
corresponding group of whites, however, only 23 percent were
attributed a high risk by the algorithm. This means that the
probability of being falsely assigned a high risk of recidivism is
twice as high for a black person as for a white person.
Continue reading
Recent Comments