Arlington, Va.—More Americans than ever need an expensive and burdensome government-issued license before they can work. Yet many of these licenses have nothing to do with improving quality or protecting public health. A new report from the Institute for Justice, which has successfully challenged licensing laws across the U.S., shows this is especially true for tour guides.

The report compares the quality of licensed and unlicensed tour guides in Washington, D.C., using a 2014 IJ victory that struck down the District’s licensing scheme as unconstitutional. IJ examined nearly 15,000 TripAdvisor reviews of guided tours from before and after the District stopped licensing guides. The data show that customers rated guided tours just as highly after licensing ended as they did before—even though 272 newly registered guides had entered the market. These new guides did not have to take the District’s 100-question licensing test—the centerpiece of the old licensing scheme—yet the quality of guided tours remained high.

“Instead of ensuring quality tours—as Washington, D.C., claimed was the point of the law—the licensing scheme only made it harder for some would-be guides to break into the business and kept others out altogether,” said Angela C. Erickson, an IJ senior research analyst and the report’s author.

The report suggests that other cities could open up their tour guide markets without spoiling tourist experiences. Charleston, New Orleans, New York City, St. Augustine, Florida, and Williamsburg, Virginia, all force guides to pass a licensing test before allowing them to work.

IJ’s findings point to a better, less burdensome way to encourage good guided tours: customers. Customers, not licensing officials, kept D.C.’s tour guides on their toes—and they still do today. Through websites like TripAdvisor and Yelp, customers demand quality service and weed out companies that fail to deliver.

The report is also the latest in a growing body of research that finds licensing of occupations as diverse as florist, construction contractor and educator does not improve services for consumers—it just shuts people out, stifling economic opportunity and consumer choice.

“By eliminating unnecessary occupational licensing, policymakers can put more people to work and give consumers more options,” said Erickson. “And, as this report shows, they can do it without compromising quality.”

For 25 years, IJ has fought for the right of all Americans to work in the occupation of their choice, free from unnecessary government interference. Currently, IJ is representing tour guides in Charleston, South Carolina, and Savannah, Georgia (which repealed its licensing requirements in response to the suit).