On January 5, 2016, a teary-eyed Barack Obama stood before a podium at the White House and announced a slew of executive actions in a final push for gun reform during his last term in office. The centerpiece of the president’s rollout was a clarified definition of what it means to be “engaged in the business” of selling firearms — a threshold that, once crossed, requires a private seller to become a licensed dealer, and perform a background check for every prospective buyer.

The action was designed to shrink the so-called private sale loophole: In the 30 states without universal background checks, it’s legal for individuals to offload weapons — at gun shows, online, or in parking lots — with no oversight. If a person sells weapons on a regular basis, however, she is supposed to obtain a federal firearms license. But the point at which a private seller must become licensed was not clear, leaving a legal gray area that some individuals exploited, funneling guns into the hands of people who would otherwise fail a background check.

With a clearer standard, the Obama White House also hoped to open the door for federal law enforcement to be more aggressive in going after people illegally dealing guns. “Anyone in the business of selling firearms must get a license and conduct background checks or be subject to criminal prosecutions,” Obama said, drawing applause from the room.

Three years later, we wanted to understand the executive action’s impact on the enforcement of rules against selling guns without a license. Using data provided by Syracuse University’s Transactional Records Access Clearinghouse, we analyzed gun prosecutions during Obama’s last year in office, and during the first two years of Donald Trump’s administration.

We found that the executive action did not result in a meaningful increase in enforcement, and cases in which an individual was charged with “unlawfully engaging in the business of firearms” have remained steady. Overall, cases focusing on illegal dealing accounted for a tiny share of overall prosecutions — about 3 percent.

According to our analysis, there were only 10 additional prosecutions filed by the Department of Justice for unlawfully selling firearms during the year Obama’s executive actions took effect. That’s an increase of about 6.5 percent — within the expected year-to-year fluctuation in prosecutions.

The Trump administration has been prosecuting more gun crimes than the Obama administration. Former Attorney General Jeff Sessions called for stricter enforcement of federal statutes related to violent crime in March of 2017, and in October of this year, his office issued a press release proclaiming that 2018 “smashes records” for gun-related prosecutions. Our analysis shows that, while total prosecutions increased in 2017 and 2018, the number of cases filed against individuals unlawfully “engaging in the business” has not noticeably changed.

This analysis is based on federal prosecutor records in which “engaging in the business” is listed as the “lead charge” — or the one that prosecutors believe is the most important in a specific case.

Federal gun cases are often referred to prosecutors by the Bureau of Alcohol, Tobacco, Firearms and Explosives. Our analysis shows that referrals by the agency for “engaged in the business” prosecutions also remained flat.

We presented our findings to Wyn Hornbuckle, the deputy director of public affairs for the DOJ. “Our strategy to reduce violent crime is to charge violent criminals with the most readily available crime,” he said in an email. A spokesperson for the ATF said that the agency’s “investigative priorities focus on armed violent offenders and career criminals, narcotics traffickers, narco-terrorists, violent gangs, and domestic and international arms traffickers.”

Adam Winker, a law professor at the University of California/Los Angeles and author of Gunfight, said federal agencies are less likely to spend time and resources investigating crimes like unlicensed selling. “The harm that comes from violating [these laws] is often quite distant,” he said. “Prosecutors are often, naturally, focused on areas where the harm is quite immediate or has already occurred.”

According to the ATF, more than 63,000 businesses and individuals hold a federal firearms license. The number of unlicensed individuals who routinely sell weapons through private sales is unknown. What it means to be “engaged in the business” of dealing firearms remains complicated. Obama’s 2016 action clarified that people who sell guns online or at gun shows — as opposed to at a brick-and-mortar store — must also register as dealers. But there is no specific number of weapons sold that trigger the need for a license. Courts have upheld convictions where only one transaction occurred or as few as two firearms were sold.

One of the most popular online sales forums where buyers can purchase firearms and bypass a background check is Armslist. The website operates as a classified section, allowing buyers to connect directly with sellers.

In February of last year, an Illinois man used Armslist to sell a Glock to a four-time felon. The buyer used the weapon to murder a Chicago police officer. After the shooting, The Chicago Tribune reported that the ATF had warned the gun dealer to stop selling guns without a license back in 2015. After telling federal agents that he would stop selling guns, the man continued selling weapons on Armslist, posting more than 200 ads.

“These laws exist, but they can be violated with impunity because they are not being enforced,” Winkler said. “You can have a law on the books, but if you’re not enforcing it out on the streets, it’s not going to have much of an effect.”

Armslist did not respond to comment for this article. In a statement following the 2016 executive action, Armslist founder Jonathan Gibbon called the measures “well-meaning, but ultimately ineffective.” The statement argues that the federal background check system should be accessible by private sellers, so they can conduct checks on their own, and that the “limited ATF and FBI resources should be spent catching actual criminals rather than scrutinizing law-abiding citizens.”

Lawmakers in Congress are pursuing another approach to reducing unregulated gun sales: universal background checks. While a bipartisan bill led by Democrats was introduced last week would not affect the ability of individuals to sell guns without a license, each sale would have to be processed by a licensed dealer, ensuring a check. The proposal is almost certain to pass the Democratic-controlled House — but very likely to face strong opposition from Senate Republicans and President Trump.