I might be slightly off the mark to what you are asking, but if I am on the right track, I suspect the move away from imprisonment as punishment is an acknowledgement of the fact that prisoners are Usually released back into the community and the experience of prison in its current state is well recognised as being detrimental to rehabilitation and reintegration. taking a more restorative and rehabilitative approach is more likely to reduce recidivism and improve outcomes. From a political point of view, it is a bit of a tightrope as much of the public vocalise their displeasure with shorter sentences and alternatives to prison Sentences, but it could be argued that governments are foregoing Possible savings in the form of resources and harm caused in order align with public sentiment. The philosophical part comes in when you consider that a governments job is to represent its public and act in accordance with the will of the majority, so even if harsher sentences and prison conditions are maintained instead of more holistic and generally more beneficial methods, the government could be acting more ethically by listening to the wider public despite less actually positive outcomes, is that what you meant?

There isn't less punishment in the US. There was a huge swing toward punitiveness, and it has nit been undone.

Imprisonment and its relationship with punishment is an interesting topic, I personally think that them two can’t be separated if we discuss about criminal punishment. I am not ready yet to provide a strong argument for this cause, this is what I am working on.💡 One of the questions that bother me is: Should we care about the impact of this kind of punishment on individual and community? This impact that I have mentioned is very difficult to be analysed... who is going to final say? This is where the politics steps in and things get put in practice.

As part of your reading, I would recommend Todd Clear's book,

Clear, Todd R. Imprisoning communities: How mass incarceration makes disadvantaged neighborhoods worse. Oxford University Press, 2009.

Of course, the responsibility of the Modern State is more linked to its ability to integrate citizens. The greatest problem of the prison systems is precisely their inability to promote the integration of prisoners. That should be their main objective. But I am afraid that in most countries they still think more about punishment than care.

Thanks to all of you for advice/suggestion, I really appreciate. I hope the research I want to do will get finished and definitely if this will happen will be shared with you. Your suggestions helps a lot. Really appreciate!

The question of imprisonment involves the question: "What is a society to do with the anti-social elements within it?"

Our two innate poles of moral feeling have always been at work when addressing these sorts of questions. And there are those who hope to "reform" the miscreants with the aim of returning them to society, or those who demand their "punishment" not only as a corrective, but as a deterrent to others.

But no matter which of these we favor, reform or punishment, the protection of society demands its more extreme miscreants be removed to protect the rest of us.

With exile no longer an option, we now exile the dangerous or habitually criminal to their own self-contained communities of wrongdoers called prisons. A rather recent invention of post-renaissance materially rich societies.

As we have grown richer, everything from the requirements of our jobs to the demands of our religions have grown easier. The same can be said of our prisons and our punishments.

The richer we are, the more liberal we become in every aspect of life.

In former times, societies were too poor to house inmates for decades, so we beat wrongdoers and let them loose, or we killed them to protect society forever from their return. Today, we imagine we can rehabilitate everyone, or feed and house them comfortably forever if necessary.

As societies continue to grow richer, we can expect this trend toward reform and hoped-for rehabilitation and away from punishment to continue.

The Theory of Dual Morality explains this behavior while examining this subject at length. Our "liberal and sympathetic" feelings grow stronger and overtake our psyches as our society grows materially richer, and our own conditions grow safer, and there is less risk. Urban areas are the wealthier locales in every society, and there is a reason why they are also the more liberal.

Since the Industrial Revolution, ever expanding material production has pushed every western society leftward on the political scale. This trend will continue as long as our wealth continues to grow.