Stephen Lurie is a writer based in Washington.

As many employees of the federal government look forward to a higher minimum wage, many in the halls of the White House itself won’t see a dime. As a White House executive order allows millions of employees to start receiving overtime pay, many at 1600 Pennsylvania Ave. still won’t be paid at all. As President Obama continues to push an economic equality agenda, about one hundred and fifty summer laborers in his own office — and hundreds of thousands like them outside it — won’t be included: the unpaid interns. So long as participants in the White House Internship Program remain unpaid, the president not only perpetuates hypocrisy but also loses an opportunity to lead a shift in labor practices throughout the country.

The costs of an internship, particularly ones in the nation’s highest office, might seem innocuous — but today that’s far from the case. To start, those taking an unpaid internship in cities like Washington can expect to spend $4,000 or more on rent and basic expenses while they work for free for three months. And the costs go beyond the simply monetary: While the White House has championed women’s equality and nondiscrimination in the workplace, unpaid interns have little to no legal protections against workplace sexual harassment and discrimination, specifically because they are not paid.

Moreover, the incongruous pledges of the president hurt those who can not afford to take an unpaid internship. The White House Internship Program, and all unpaid internships, entrench economic inequality and discriminate against low-income families: Only the wealthy can afford to pay rent and expenses in order to work for free. Instead of offering more “ladders of opportunity into the middle class,” the president and other employers are handing prestigious internships — often key to future employment — to those already in the lead. Of last summer’s interns, almost a third were from Ivy League schools, and many hailed from administration-linked families or major donors. The president says economic inequality is “the defining challenge of our time,” but by supporting unpaid internships he widens the income gap right at the very entry to the workforce.

With such a blatant contradiction of values, and a missed opportunity to act without a gridlocked Congress, one has to wonder the reason for the inconsistency. Since the White House did not respond to a request for comment, we are left to surmise its reasoning.

Optimistically, the White House’s use of unpaid interns could be down to inertia and ignorance: Because the interns have always been unpaid, perhaps it just hasn’t occurred to the White House to fix that. But outside groups like the Fair Pay Campaign have been pressuring the Obama administration, and there is no sign that it plans to change the policy.

Pessimistically, then, it seems more likely that unpaid internships have been a deliberate calculation by the administration. They have decided that, perhaps, offering payment in an internship program already facing nepotism allegations would risk more attention. Or perhaps the administration has concluded that it is economically expedient to get a lot of added work-hours at no cost to them. Alas, that decision would be equally indefensible: Economic expediency at the price of human dignity doesn’t meld with Obama’s campaign against economic inequality. Besides, even in sequester-ridden Washington, intern stipends would be a drop in the bucket. Paying decent stipends for the large summer session would cost $600,000 ($4,000 per intern), well worth the labor they receive and the individuals they hope to develop.

Ultimately, whether the choice to retain unpaid interns in the face of a rising chorus of dissent is based on ignorance or economic expedience doesn’t really matter. There’s no good excuse for the president of the United States to rely on unpaid labor, particularly as the practice consistently violates his stated convictions. As the debate over unpaid internships amplifies, he holds a unique power to shift this practice in the entire economy. The decision to begin paying White House interns this year is fully within Obama’s grasp. If the administration is fully committed to the reform, it could even seek to unilaterally change labor regulations, just like it has explored with overtime pay.

On raising the minimum wage, Obama said that as “a chief executive, I intend to lead by example.” Mr. President: Unpaid internships contradict your commitments and your economic agenda. Lead by example: It’s time to pay your interns.