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The Effects of Sanction Intensity on Criminal Conduct - JDAI Helpdesk

The Effects of Sanction Intensity on Criminal Conduct - JDAI Helpdesk

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0.55. Raising the threshold results in a slight loss in the ability to predict who will not<br />

commit a serious <str<strong>on</strong>g>of</str<strong>on</strong>g>fense, but the trade-<str<strong>on</strong>g>of</str<strong>on</strong>g>f is small and favors increased public safety.<br />

This alternative threshold is close enough to the original 0.5 cut-<str<strong>on</strong>g>of</str<strong>on</strong>g>f that the results <str<strong>on</strong>g>of</str<strong>on</strong>g> the<br />

present study are unlikely to be greatly affected, and as a matter <str<strong>on</strong>g>of</str<strong>on</strong>g> policy any change<br />

would depend <strong>on</strong> the extent to which the probati<strong>on</strong> agency was willing to trade<br />

c<strong>on</strong>siderable resource savings for a small potential decrease in false positives. Twelve<br />

per cent <str<strong>on</strong>g>of</str<strong>on</strong>g> the full sample (323 <str<strong>on</strong>g>of</str<strong>on</strong>g>fenders) had risk scores between 0.5 and 0.55, and<br />

would not have been eligible for low-intensity supervisi<strong>on</strong> at the higher classificati<strong>on</strong><br />

threshold.<br />

One limitati<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> these diagnostic tests is the very low prevalence <str<strong>on</strong>g>of</str<strong>on</strong>g> serious<br />

recidivism post-risk assessment in the sample as a whole, which led to a large number <str<strong>on</strong>g>of</str<strong>on</strong>g><br />

false negatives. This in turn reduces the ability <str<strong>on</strong>g>of</str<strong>on</strong>g> the model to predict true positives<br />

(true low-risk cases), which is the ultimate goal <str<strong>on</strong>g>of</str<strong>on</strong>g> the risk assessment process. This is an<br />

issue that is unlikely to be easily overcome, because serious <str<strong>on</strong>g>of</str<strong>on</strong>g>fenses like homicide and<br />

rape will always be relatively rare events. However, the predicti<strong>on</strong> model can be applied<br />

to any new probati<strong>on</strong>er entering the Philadelphia APPD, so the potential exists for more<br />

data to be collected <strong>on</strong> low and n<strong>on</strong>-low risk clients, their serious <str<strong>on</strong>g>of</str<strong>on</strong>g>fending, and the<br />

performance <str<strong>on</strong>g>of</str<strong>on</strong>g> low risk <str<strong>on</strong>g>of</str<strong>on</strong>g>fenders under low-intensity supervisi<strong>on</strong>. <str<strong>on</strong>g>The</str<strong>on</strong>g>se data could be<br />

added to an analysis like those presented here, in order to c<strong>on</strong>duct c<strong>on</strong>tinuous validati<strong>on</strong><br />

and refinement <str<strong>on</strong>g>of</str<strong>on</strong>g> the model.<br />

Our analysis shows that the model is also somewhat successful in ensuring that<br />

<str<strong>on</strong>g>of</str<strong>on</strong>g>fenders who might not have committed <strong>on</strong>e <str<strong>on</strong>g>of</str<strong>on</strong>g> the most serious <str<strong>on</strong>g>of</str<strong>on</strong>g>fenses, but could be<br />

c<strong>on</strong>sidered serious <str<strong>on</strong>g>of</str<strong>on</strong>g>fenders by other standards, are not channeled into receiving less<br />

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