The entire concept of using statistical algorithms to 'predict crime' is wrong. It's just a kind of stereotyping.<p>What needs to happen is a consideration of the social-justice outcomes if 'profiling algorithms' become widely used. Just as in any complicated system, you cannot simply assume reasonable looking rules will translate to desirable emergent properties.<p>It is ethically imperative to aim to eliminate disparities and social inequalities between races, even if, and this is what is usually left unsaid, <i>judgments become less accurate in the process</i>.<p>Facts becoming common knowledge can harm people, even if they are true. Increasingly accurate profiling will have bad effects at the macro scale, and keep marginalized higher-crime groups permanently marginalized. If it were legal to use all the information to hand, it would be totally rational for employers to discriminate against certain groups on the basis of a higher group risk of crime, and that would result in those groups being marginalized even further. We should avoid this kind of societal positive feedback loop.<p>If you accept that government should want to avoid a segregated society, where some groups of people form a permanent underclass, you should avoid any algorithm that results in an increased differential arrest rate for those groups, <i>even if that arrest rate is warranted by actual crimes committed</i>.<p>"The social norm against stereotyping, including the opposition to profiling, has been highly beneficial in creating a more civilized and more equal society. It is useful to remember, however, that <i>neglecting valid stereotypes inevitably results in suboptimal judgments</i>. Resistance to stereotyping is a laudable moral position, but the simplistic idea that the resistance is costless is wrong. The costs are worth paying to achieve a better society, but denying that the costs exist, while satisfying to the soul and politically correct, is not scientifically defensible. Reliance on the affect heuristic is common in politically charged arguments. The positions we favor have no cost and those we oppose have no benefits. We should be able to do better."<p><pre><code> –Daniel Kahneman, Nobel laureate, in Thinking, Fast and Slow, chapter 16</code></pre>