A $15 per hour minimum wage has become a national U.S. rallying cry from workers seeking middle-class security. But while double the current minimum, $15 has its own limitations — and risks uncontemplated social consequences.

Why it matters: A $15 wage may be enough to buy a small home in some parts of the U.S., and will increase the living standards of millions of Americans. But what's apparent on the map above is that it is barely sufficient for a studio apartment in the big cities, and it could upset workers already earning $15 and more.

Driving the news: In 2019, New Jersey, Illinois and Maryland have enacted laws to bring the minimum wage up to $15 in the near future. Major cities like New York, Seattle and San Francisco had previously done so, as have major corporations like Amazon and Disney. These moves have made $15 the target across the country, but they also create new expectations that employers must consider.

Take El Centro, a city close to the Mexican border in California, where the median wage is $14.76, per the Bureau of Labor Statistics. Because of El Centro's lower prices, the purchasing power of $15 there actually comes to about $16.80, according to a government formula that reconciles the geographic value of wages from city to city.