In some ways, a central problem of our correctional system is that it has not sufficiently adjusted to social, economic, and political changes in our society. This is one reason why the United States has such a disproportionately large prison population and why glaring injustices exist within the criminal justice system, which cannot be understood as separate from the correctional system. The fact that nearly 1.5 million Americans are imprisoned demonstrates that there is a real disconnect between society and our correctional institutions.
However, in terms of how correctional institutions actually work, there have been some changes, and some of these changes have been a consequence of rapidly expanding prison populations since the 1980s. One reason is that there has been an increased focus on providing mental health services, education, vocational training, drug rehabilitation, and other programs focused on rehabilitation rather than punishment. Sadly, though, these services have become stretched by expanding prison populations that have not been matched by funding, so they are inadequate. There has also been a shift away from incarcerating juveniles, who have been less likely to be determined delinquent by judges.
These changes reflect both broader social changes and current scholarship about criminal behavior. However, the predominant trend in the correctional system remains mass incarceration, which, separate from ethical and social justice concerns, makes reform of the correctional system more difficult.