The United States’ penal system has been undergoing many changes in recent years. These changes range from reducing prison sentences to changing rehabilitative programs for prisoners, and are based on studies and research looking at what policies and strategies are most effective and most beneficial to society as a whole. Many of these changes have been or are being pushed due to the huge growth in the United States’ prison population over the past four decades, which has not only resulted in prison overcrowding, but has become a huge burden on taxpayers who have to pay for each inmate being kept in prison. This epidemic of incarceration has caused an increasing number of people in the United States to question the effectiveness of the current approach to imprisonment in the justice system, as well as many other aspects of the penal system, such as rehabilitation, education, and sentencing. In particular, there is a lot of criticism regarding mandatory sentencing for nonviolent crimes, such as drug offenses, which might be better addressed by assigning probation, community service, a fine, or sending the offender into a treatment program, if necessary. After all, studies have found that having nonviolent offenders in prison for too long is actually more likely to make them repeat offenders, so that the prison becomes a sort of revolving door for many of its inmates. Some states have already begun researching alternate methods of sentencing in order to reduce prison population, and have had some measure of success, though the nation as a whole still has a long way to go. Another more in-depth method to reducing prison population is through rehabilitation, essentially ensuring that the rate of incarceration is reduced simply by virtue of the fact that fewer offenders return to the prison, and instead re-enter society as law-abiding citizens. The latter method is far more difficult to tackle, as each individual convicted of a crime has a different story and different reasons for breaking the law, and as such, there is still a lot of room for discussion on how to improve rehabilitative programs and also to make these programs more available to the inmates who need them.