Employers may argue that professional experience gained via an internship pays for itself - which is hopefully the case, as most of the presidential candidates are not prepared to pay you to work for them.

A new study has revealed that only one presidential hopeful out of a total of 16 candidates pays their interns.

Bernie Sanders, Vermont Senator and Democrat, pays his interns $10.10 per hour, as reported by The Washington Post.

Christina Greer, assistant professor of political science at Fordham University, and Alexis Grenell, a political strategist and columnist, hired a student at $15 per hour to find out how each candidate employs interns.

Despite many candidates discussing how to reduce student debt, which leaves seven out of 10 students down $29,000 on average upon graduation, the vast majority of the politicians use a glut of unpaid interns to propel their White House success.

Unpaid internships are also a political issue - there is a racial divide between the median wealth of white households, which is 10 and 13 times more than Hispanic and black households respectively.

In August, Hillary Clinton tweeted out an internship application, asking for a CV and two letters of reference. A few days later, she was asking students to tweet her about how “student loan debt makes you feel.”

Ms Clinton has also come under fire for accepting $675,000 speaking fees from Goldman Sachs, and has earned $153 million in speaking fees alongside her husband since 2001. Mr Sanders has revealed that he made just over $1,800 for three speeches last year and has given all the money to charity.

Republican Jeb Bush has said the opportunity gap is the “defining issue of our time” and Marco Rubio has protested against “upward-mobility stagnation”. Neither offer interns a salary.

Republican Ben Carson called for public universities to pay student loan interest. Mr Carson advertised for “paid” internships, but only covers food and travel expenses.

The only unanswered question regards real estate tycoon Donald Trump, who has accused federal government of making profit at the expense of students. He does not advertise for interns for his campaign, and did not respond to calls from The Washington Post. However he does pay his Trump Entertainment Resorts interns $10 per hour.

The candidates may not vary much on pay, but they do vary on what they require during the application process.

Former chief executive Carly Fiorina also covers expenses, and requires applications to submit a CV and respond to a series of questions. New Jersey Governor Chris Christie asks for a CV and a cover letter. Marco Rubio, the only one of these three politicians that is ascending the polls, asks for a CV, cover letter, references and answers to a series of questions.

The candidates that only ask for a CV are Republicans John Kasich, Mike Huckabee, Lindsey Graham, Rand Paul, Ted Cruz, Rick Santorum, George Pataki and Jeb Bush, as well as Democrat Martin O’Malley. Mr O’Malley is the only one on this list who supports an increase in the minimum wage.