When National Review’s critic at large, Kyle Smith, last week published a piece with the headline “We Were Wrong About Stop-and-Frisk,’’ people noticed.

Smith and National Review are conservative. Like many conservatives, they had predicted that if Mayor Bill de Blasio of New York fulfilled his campaign pledge to end stop-and-frisk — the police practice of stopping, questioning, and patting down people merely because they seemed suspicious — crime in the city would go up. But that’s not what happened.

In the four years since de Blasio became mayor, conceded Smith, major crime has declined “to the lowest rates since New York City began keeping extensive records on crime in the early 1960s.’’ The left-wing mayor was right about stop-and-frisk, and the right-wing journal said so. In so doing, it displayed more loyalty to truth than to theory.

Following facts where they lead is a principle easier to state than to live up to, particularly when the facts upend our preconceptions. Some public-policy debates are endless because they are rooted in disagreement over fundamental principles — the question of capital punishment, for example. But other disputes ought to be resolvable, at some point, by facts on the ground. Advocates of an aggressive stop-and-frisk policy were certain the only alternative was higher crime rates. They were mistaken. The honest response is to acknowledge it and end the debate.

Another controversy that should be laid to rest is the impact of minimum wage laws.

When government raises the lowest hourly wage at which a worker may lawfully be employed, does it help those at the foot of the economic ladder? The issue has been fought over for decades. Yet reality repeatedly renders the same verdict: Artificially hiking minimum wages makes it harder to employ unskilled workers. Raising the cost of labor invariably prices some marginal laborers out of the job market. Advocates of higher minimums may wish to ensure a “living wage’’ for the working poor. Yet the result is that fewer poor people get work.

Two years ago, Seattle’s hourly minimum wage jumped to $13, the second hike in less than a year. Before the legislation was enacted, there had been the usual arguments pro and con. But the impact of Seattle’s law is now a matter of facts, not theory. And those facts confirm what opponents of the increase had foretold: Minimum wage hikes hurt the poor.

In a major research paper last summer, economists commissioned by the city of Seattle reported that the hike to $13 an hour caused a decline in the employment of low-wage workers. For those who remained employed, it caused a sharp cutback in hours. When the gain from higher hourly wages was set against the loss of jobs and hours, the bottom line was stark: “The minimum wage ordinance lowered low-wage employees’ earnings by an average of $125 per month in 2016.’’

Another 2017 study, by Harvard Business School scholars, analyzed the effect of minimum wage hikes on San Francisco-area restaurants. The upshot: Every $1 increase in the mandatory minimum wage led to a 14 percent increase in the likelihood that a median-rated restaurant would go out of business. Decades of empirical research, dating back to the first federal minimum wage law, have reached similar conclusions.

In 18 states this month, minimum wages are going up. Will those changes make unskilled workers more employable? Will the hours they work be increased? As in Seattle and the Bay Area, these questions will have answers. Soon enough, fresh data will shed even more light on the question of what happens to unskilled laborers when their labor is made more costly. Maybe that will be the moment when someone more loyal to truth than to theory publishes a reality-based essay conceding: “We Were Wrong About the Minimum Wage.’’

Jeff Jacoby can be reached at jacoby@globe.com. Follow him on Twitter @jeff_jacoby.