The recent news that Hillary Clinton's presidential campaign seriously considered including a Universal Basic Income as a policy proposal should not surprise us. The idea of a uniform, regular payment to all citizens is not new. It was proposed as early as 461 BC by the Greek politician, Ephialtes, to enable all people, even plebs, to participate in the polis, and has emerged at various stages through history, with a recent surge in popularity since the 2007-8 financial crisis. basic income is now being considered seriously by (mostly opposition) parties around the world.

Pilot projects, including here in the U.S., have been promising, with more underway. Particularly in the face of an increasingly precarious labor market and concerns that robots could soon replace human workers, the idea is beginning to capture the public imagination. It is typically seen as an idea of the left, but has also been embraced by those on the right. The time for a basic income may well be drawing nigh.

Possible models for a basic income vary, including payments conditional on certain behaviors, payments only when other income falls below a certain level, and an unconditional monthly payment to everyone. But common to all of these models is a lack of attention to how people with disabilities would fare.

In the United States, people with disabilities are already eligible for a basic income of sorts. They receive government benefits for which they do not have to work, either Social Security Disability (SSDI) and/or Supplemental Security Income (SSI), and remain eligible as long as they are disabled. However, there are serious downsides to the existing disability benefits system which could, in theory, be solved with a basic income.

Currently, when a person first becomes disabled, they often have to spend long periods with little to no income while they wait for their benefits to be approved. Once approved, depending on whether they are on SSI or SSDI, any work income may result in a cut in their benefits income.

Given that the ability of people with disabilities - particularly those with mental illness - to work may fluctuate over time, and that they may only be qualified for poorly paid, insecure jobs, many choose to stick with their low but reliable benefits income rather than unpredictable low-wage income. Not only can work have therapeutic benefit, but not working can further stigmatize people who already face discrimination from broader society. Social Security programs designed to encourage disability recipients to go back to work are well-intentioned, but, in practice, are confusing, hard to navigate, and persuade very few people to take that step.

In general, the bureaucracy associated with applying for and proving continued eligibility for disability benefits is so complex that health providers often spend far too much time helping clients with benefits, eating into precious time that should be spent addressing their illness.

A basic income system could, in theory, address all of these problems. People with disabilities would simply receive the same basic income as everyone else, thereby avoiding stigma, difficulties of moving from benefits income to paid work, and the perpetual entanglement with a frustrating and often overwhelming bureaucracy.

So far, however, none of the models proposed has provided adequate detail about what a basic income would mean in practice for people with disabilities. Pilot projects in the U.S. tend to exclude people on SSI/SSDI as they already receive cash income without working so aren't suitable to test the idea on, plus their SSI/SSDI eligibility could be affected by any additional income.

Even the most well developed models, such as that described by Guy Standing, a leader of the global basic income movement, in his new book, "Basic Income: A Guide for the Open-Minded," do not tell us enough. Standing's model would see an unconditional, monthly payment to all people "normally resident" in a nation, of an amount adequate to meet a person's basic needs - about $1,000 in the United States. The same amount would be paid to everyone, regardless of wealth or other income, although the wealthier would be subject to higher taxes to even out the implied inequality.

Benefits such as food stamps and the Earned Income Tax Credit (EITC) would be eliminated; others, such as health care and free education, would remain. The cost of the basic income would be paid for by higher taxes on, and less subsidies for, the rich, plus savings from scrapped benefits programs, and administrative savings from removal of eligibility assessments and means-testing.

Standing recognizes that his model could leave people with disabilities, who are unable to earn additional income, on the edge of poverty. To counter this, he recommends a special disability supplement over and above the basic income. The question is, would that supplement create the same problems that the current benefits system creates, with long approval wait times and disincentives to work? Also, would there be different supplement levels, and how would those be decided?

Standing's model is thin on these details. Obviously receiving a basic income would remove the risk of possible destitution and associated anxiety, which would be a huge improvement on the current system. But more thought must be given to how a basic income would accommodate people with disabilities, if it is to be truly transformative.

And Standing's model, which gets closer than any other to addressing the needs of people with disabilities, may not be what we get. The basic income could well come to fruition, given its appeal across the political spectrum, but it will likely be through a process of political compromise. Proponents on the right see the basic income as an opportunity to strip government down to its bare essentials, supplanting all social services, including health care, housing support, disability benefits, education, childcare, and so on. People with disabilities would most certainly be worse off in such a scenario.

People with disabilities and those who live, work with, and support them need urgently to educate ourselves about what a basic income is and what it could mean for us. We must begin to take part in the conversation now, to ensure that if a basic income does become a reality, it does so in a way that benefits people with disabilities, rather than leaving them even more vulnerable than they currently are.

Annie Harper is a cultural anthropologist in the Yale School of Medicine and a Public Voices fellow with the OpEd Project.