Source: (2000) Crime and Delinquency. 46(3): 299-314The central promise of experimental criminology is its potential to lower the extraordinarily high incarceration rates in the United States. Imagining the counterfactual scenario of medicine without experiments suggests that major changes would be much slower and less effective without randomized field trials (RFTs). Imagining alternatives to our current high rates of imprisonment suggests that we might discover more effective programs for crime prevention without prison, as well as for crime prevention without courts. Research advances in the use of moral appeals and other mechanisms of attaining compliance through socialization rather than sanction threat provide a fertile research agenda. Carrying out that agenda with RFTs would be the shortest pat to reducing incarceration rates.