In the six years since the first states legalized marijuana, the political, legal, and social landscape surrounding the drug has been in a near-constant state of flux. At the federal level, marijuana remains a Schedule I drug, a classification the DEA reserves for "drugs with no currently accepted medical use and a high potential for abuse." On the Schedule I list along with marijuana are heroin, LSD, and peyote, among others. What's less dangerous? Cocaine, a Schedule II drug, and anabolic steroids, which are on Schedule III.

That 31 states and Washington have legalized marijuana in some form, only to see the sky, moon, and stars remain firmly in place, indicates that marijuana is far less problematic than detractors claim. In Colorado, one of the first two states to legalize recreational use of the drug, teen use actually fell in the years following legalization.

As states and cities rethink their attitudes toward marijuana, drug enforcement has taken center stage. For a while, even the federal government seemed to be rethinking the drug. The Cole Memorandum, issued in 2013, stated that the Justice Department would largely take a hands-off approach to marijuana in states that legalized marijuana.

This year, Attorney General Jeff Sessions rescinded the Cole Memorandum. But with almost two-thirds of the states in various stages of legalization, the genie is clearly out of the bottle. Even a committed drug warrior like Jeff Sessions will not get it back in. Philadelphia District Attorney Larry Krasner proved the point by announcing that his office would no longer pursue charges against marijuana possession.

Some have reasonably argued that this is simply legalization by other means, and on some level it is. But it is important to remember that Krasner's move on marijuana followed in the footsteps of rules that, then councilman, now Mayor Jim Kenney, former Mayor Michael Nutter, and former District Attorney Seth Williams implemented starting more than four years ago. These rules gave Philadelphia police the option to issue simple citations for possession of small amounts. Krasner's decision no longer to prosecute these cases was a continuation of forces well in motion.

But what does this de facto legalization accomplish?

First, it puts an end to the ruination our judicial system metes out to peaceful people over what is very clearly a harmless practice. Marijuana's inclusion on the Schedule I list aside, people know marijuana to be far more benign than other substances the federal government does not prohibit, such as tobacco, alcohol, and even sugar. The only reason that marijuana ruins lives is because busybodies demand that the government imprison people who use it. In an attempt to curb marijuana use, the judicial system has done far more damage to people's lives than marijuana itself ever could.

Second, dropping pointless punishments saves taxpayer money and frees up police resources to focus on crimes that do harm people. Importantly, it also helps to restore the image of the police in the eyes of the people. Requiring the police to arrest people for using a drug many agree is largely harmless simply encourages people to view the police as the enemy, and it is not unreasonable for them to do so.

And this brings us to perhaps the best effect of Krasner's refusal to prosecute marijuana possession. The states that have legalized marijuana are examples to other states that legalization actually can make communities healthier. So too can Philadelphia's district attorney be an example for other DAs across the country.

What we tend to forget as we look to federalize every element of American life is that offering a one-size-fits-all answer for problems tends to eliminate any number of creative approaches that emerge as people work to address various political, legal, and social issues. Thirty-one states, the District of Columbia, and now Philadelphia have all found a better way to deal with marijuana. We should all celebrate their examples, most of all Philadelphia's own.

Antony Davies is associate professor of economics at Duquesne University. James R. Harrigan teaches in the department of Political Economy and Moral Science at the University of Arizona. They host the weekly podcast, Words & Numbers.