Some countries have a very, very tough penalty, the ultimate penalty.

And by the way, they have much less of a drug problem.

This isn't the first time the Trump Administration has taken a tough stance on crime.

Attorney General, Jeff Sessions, sent out a memo directing prosecutors to charge and pursue the most serious, readily provable offense.

And in the past, Democrats too have been proponents of tougher sentences.

When you commit a third violent crime, you will be put away and put away for good.

Three strikes and you are out.

But do longer and harsher sentences actually work to deter crime?

I think the general answer to that is probably not.

Michael Cholbi is a Professor of Philosophy at Cal Poly.

It seems to be that most of the studies that have been conducted have concluded that in fact the severity of punishments doesn't have a lot to do with the overall level of crime.

So to give you just a couple of examples, the United States has implemented since the 1990s a great many mandatory minimums.

So these are laws that require that offenders be sentenced to a certain mandatory minimum.

Usually, the mandatory minimums are higher than what the offender would ordinarily be sentenced with.

And the studies that have conducted on this suggest that, you know, we have seen a drop in crime.

But only a small fraction, maybe 5% of that can be attributed to these mandatory minimums, these harsher sentences.

So what can be attributed to the drop in crime over the years?

In 1994, President Clinton signed the three strikes bill.

It mandated life sentences for offenders who had more than two prior convictions.

Since then, the amount of violent crimes has been cut by nearly half.

However, experts say only a modest amount of the drop in crime could be attributed to Clinton's bill.

A Government Accountability Office report in 2005 found that the biggest reasons for the drop in crime were increased employment, increased police presence, and an aging of the population.

To fully understand why harsher and longer punishments don't really deter crime, Cholbi says we need to understand how criminals think.

I think, again, we assign much more significance to the probability of the punishment occurring than we do to the severity of it.

Take John, for example.

John wants to steal this apple.

According to Cholbi, John isn't thinking about how long he'd go to jail for theft.

But instead he's thinking about whether or not he'd get caught stealing the apple.

To deter John from stealing apples in the future.

It might make more sense to increase the probability that he'd get caught rather than increase the severity of his sentence.

But would something as severe as the death penalty be a deterrent?

Probably not, except in atypical or very specific circumstances.

It turns out that states with the death penalty have had higher murder rates.

And studies have shown that if capital punishment has any deterrent affect at all, it may be too small to be detected.

So why do politicians insist on longer and harsher sentences when there's no proof that they actually deter crime?

It's important to realize politicians are vote maximizers.

Jim Copland is the Director of Legal Policy for the Manhattan Institute.

And so they're not policy wonks who are trying to go through policy studies and come up with the optimal policy.

What they're trying to do within their viewpoint is push policies that they think they can sell to their constituencies.

So being tough on crime is something that has been a political selling point by and large.

As criminal justice reform gains popularity, many worry that the release of prisoners will lead to an increase in criminal activity.

We see a lot of red states that are trying to reduce their prison populations.

And if you do that smartly, you can do that without leading to an uptick in crimes.

From 1999 to 2012, New York decreased their state prison population by 26%, while the nationwide state prison population increased by 10%.

During that time the violent crime rate in New York dropped by 31%, while the national rate only dropped 26%.

New York accomplished this with a combination of changes in policy and practice.

Mandatory minimums were reduced, and in some cases eliminated.

And parole approval rates grew significantly.

So if politicians are serious about being tough on crime they should focus on catching criminals, rather than longer sentences.