In an experiment in Liberia, researchers took 999 of the most violent, high-risk criminals in their capital, and for only $535 of expenses per person (nothing to these kinds of programs or compared to the cost of crime and prisons), they bought 20-50% lower incidents of crime in that population for a year. The treatment was asking 1500 candidates if they wanted therapy – 2/3 of them said yes – and they ran a cheap cognitive behavioral therapy (CBT) course with them.
CBT was then brought to Chicago youths with similarly positive results in three separate randomized controlled trials. Graduation rates rose and crime rates fell, crucial in bringing a new generation out of poverty with access to better opportunities.
Image By Jty33 (Own work) CC BY-SA 3.0
In the two studies participation in the program reduced total arrests during the intervention period by 28–35%, reduced violent-crime arrests by 45–50%, improved school engagement, and in the first study where we have follow-up data, increased graduation rates by 12–19% […] These large behavioral responses combined with modest program costs imply benefit-cost ratios for these interventions from 5-to-1 up to 30-to-1 or more.
If the improvements in participants’ high school graduation lead to other future benefits such as increased earnings or longer life expectancies, these estimates may understate the full value of the program’s social benefits
“Thinking, Fast and Slow?” Heller, et al
To investigate, we recruited 999 of the highest-risk men in Liberia’s capital, generally aged 18 to 35. Most were engaged in part-time theft and drug dealing, and regularly had violent confrontations with each other, community members, and police.
Men who received therapy reduced their antisocial behavior dramatically. Within a few weeks, for instance, drug dealing halved and thefts fell by a third, compared to controls. With therapy alone, these eﬀects diminished after a year. When therapy was followed by cash, however, eﬀects were lasting. For example, a year later, those who received both therapy and cash were 44% less likely to be carrying a weapon, 43% less likely to sell drugs, and reported lower aggression. In the control group, men reported stealing almost once per week on average, and with therapy and cash this fell nearly 40%—equal to 25 crimes per year, per person.
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