But evidence that any such effects are relatively small has been piling up for several decades. A groundbreaking study published in 1993 by the economists David Card and Alan Krueger examined a minimum-wage rise in New Jersey by comparing fast-food restaurants there and in an adjacent part of Pennsylvania. It found no impact on employment.

This prompted other economists to test the standard theory. This year, the British government asked the economist Arindrajit Dube to review the results accumulated over the last quarter-century. Mr. Dube reported the sum total of the research showed minimum-wage increases raised compensation while producing a “very muted effect” on employment.

The patchwork nature of recent minimum-wage increases — the rate rising in some jurisdictions while staying the same in adjacent areas — is offering new opportunities for research.

Consider, for instance, the situation along the New York-Pennsylvania border. New York State has been raising its minimum wage since 2016. On Tuesday, the legal minimum will reach $11.80 outside New York City. Pennsylvania, meanwhile, is among the 21 states where the $7.25 minimum remains in force. In September, researchers at the Federal Reserve Bank of New York found that wages have climbed significantly in counties along the New York side of the state line, again without a discernible difference in the pace of employment growth.

For most companies, the bill is relatively small, and it can be defrayed by giving less money to shareholders, or by raising prices. Opponents often argue minimum-wage increases will encourage automation, but the point is easily overstated. Companies constantly invest in technology: McDonald’s is installing self-order kiosks across the United States, not just at places with higher minimum wages. And instead of replacing workers with robots, companies may choose to invest in technology that enhances the productivity of their work force.

More than doubling the current federal standard would be a significant change, and it is not without risk. It is possible that a national $15 standard would produce the kinds of damage critics have long predicted; the Congressional Budget Office puts the potential increase in unemployment somewhere between zero and 3.7 million people, essentially acknowledging the effects are unpredictable. Workers may be most vulnerable in areas where prevailing wages are relatively low. In California, for example, the minimum wage for large employers (more than 25 workers) will rise to $13 an hour on Wednesday. That is unlikely to cause problems in San Francisco — but the new minimum is quite close to the median hourly wage of $15.23 in the Visalia metropolitan area in the Central Valley. The federal minimum would apply to metropolitan areas like Daphne, Ala., and Sumter, S.C., where the median worker earned less than $15 an hour in 2018.

One simple corrective, proposed by Senator Michael Bennet of Colorado, would be to include exemptions from the $15 standard for low-wage metropolitan areas and rural areas.