Furthermore, the author argues, the trend toward increased incarceration has had not a measurable impact on crime rates. Instead, stringent community-based sanctions have had some effect on reducing street crime. Parole failure rates are increasing at the same time that more offenders are going to prison and serving longer sentences, mainly because there is a lack of an adequate structure in correctional decision making, and because the public believes that incarcerating more offenders enhances public safety. To reduce overcrowding, the criminal justice system must sentence nonviolent offenders to intensive supervision, electronic monitoring, or community service instead of prison.