Senate Minority Leader Chuck Schumer (D‑N.Y.) introduced a bill late last month to decriminalize marijuana nationally. It’s high time that happened. Ending the federal prohibition on marijuana — and the disastrous War on Drugs more broadly — is decades overdue.

As of today, nine states — Colorado, Washington, Oregon, Alaska, California, Nevada, Maine, Vermont and Massachusetts — have legalized marijuana for recreational use. As Congress debates decriminalization, it’s worth asking: How are those states faring?

Frankly, just fine. Critics often argue that liberalizing marijuana spurs drug or alcohol use, increases crime, diminishes traffic safety, harms public health and lowers teen educational achievement.

However, a growing body of research concludes that none of those outcomes have materialized in states where marijuana is now legal.

In a recent paper, co-authored jointly with Angela Dills, we find that legalization in Colorado, Washington, Oregon and Alaska had only a slight impact on marijuana use overall and no discernible impact on other outcomes such as traffic accidents, public health and violent crime rates — a far cry from marijuana opponents’ dire depictions.

In contrast to the idea that legal marijuana may be driving the current opioid addiction crisis, we find preliminary evidence in another study that legalization may actually be associated with reduced teen usage of heroin and cocaine. 

While each of those four legalizations occurred recently (meaning before-and-after comparisons are limited), the available data consistently suggest that states have had enjoyed positive outcomes after liberalizing marijuana. Other studies find a similar relationship between states with medical marijuana and lower opioid prescribing.

Nevertheless, federal decriminalization of marijuana is necessary to clear up legal uncertainties and give states greater freedom in regulating the substance, without fear of reprisal from the government.

Individual states have liberalized marijuana in various ways over the past few decades, yet conflicts have often arisen between federal and state law enforcement agencies working under different legal regimes. Decriminalization would obviate the need for legal run-ins, and it would give states greater autonomy in safely regulating (and taxing) the substance.

More importantly, marijuana decriminalization would free up federal law enforcement resources to fight crime that’s actually pernicious, and it would help bring an end to the colossal racial injustices that pervade drug policing.

Absurdly, police arrest more people for marijuana violations in the U.S. than for all violent crimes combined. An ACLU study found that between 2001 and 2010, police made over 7 million arrests for marijuana-related activity — one apprehension every 37 seconds.

During this same period, blacks were four times more likely than whites to be apprehended despite almost equivalent use rates.

Those in favor of marijuana prohibition may like to think that such widespread drug policing is necessary because it primarily targets and catches drug smugglers and traffickers. This could not be further from the truth.

Data from the Drug Policy Alliance reveal that 89 percent of arrested individuals are charged with possessing small amounts (usually no more than a few grams) of the substance.

Make no mistake: The longer our federal policies continue to criminalize marijuana, the longer our nation continues to suffer from excessive, costly and disproportionate federal prosecution against petty marijuana possession.

Regrettably, many members of the Trump administration are deeply hostile toward sensible marijuana policy reform. Attorney General Jeff Sessions has expressed a particularly flawed understanding of the drug and its effects.

He has repeatedly made inaccurate assertions that legalization causes greater use of opioids and that law enforcement is seeing “real violence” due to higher marijuana use.

In January, Sessions announced the reversal of Obama-era policies shielding states with legal marijuana from federal prosecution, citing the need to reduce violent crime, fight the nation’s drug overdose crisis and weaken criminal organizations.

Ironically, this policy reversal threatens to worsen these very outcomes, needlessly strain law enforcement resources and cause confusion in states where legal marijuana has already generated hundreds of millions of dollars in tax revenue.

But as our elected officials debate decriminalization, we urge them to look past this fear-mongering and focus on data-driven evidence about marijuana. The facts so far are clear: State marijuana legalizations and medicalizations have had little-to-no impact on marijuana use, other drug abuse, alcohol consumption, violent crime and traffic accidents.

Meanwhile, our nation continues to suffer from excessive and racially unjust marijuana policing. Reforming our outdated drug laws is long overdue.