To discriminate is to evaluate someone based on characteristics other than merit; sometimes it involves acting on that assessment.
In actual fact, unemployed people experience many kinds of discrimination. There is ample evidence, for example, that it is easier to find a job when you already have one. This is largely because to potential employers someone who is employed is already demonstrating some basic minimum traits (showing up at work, behaving reasonably in a workplace, keeping up some level of productive behavior, etc.).
However, it would not be logical to assume that every person who is unemployed does not possess similar traits, only that the traits are only not evident in the present. Nonetheless, the bias exists among employers.
Some even argue that the longer a worker stays out of work, the more their skills degrade—for example, the jobless often do not gain exposure to the latest techniques in certain fields or through lack of practice they lose proficiency. This is debatable. Certainly, it cannot be applied reasonably to everyone on a blanket basis.
At this writing in mid-2016, in most of the United States to act in the labor market on the basis of biases such as I have presented is not illegal, although it is neither kind nor fair nor, in many cases, sensible. In my view, it is not valid to refuse to hire people on the basis that they are unemployed.
There are other conclusions, however, that may be validly drawn from unemployment.
People without jobs are not likely good risks for a bank loan, unless they can show unearned income. Unemployed people are not likely to be paying taxes, they are likely to suffer from unemployment psychologically and require help. Some studies show that people who lose their jobs during great economic crises tend to have lower future incomes and life expectancy. It would be valid to make some decisions on the basis of these effects of unemployment and take actions that might discriminate, sometimes for the good of the jobless person.
This is a repost from my replies to questions posted on Quora, a question-and-answer site where questions are asked, answered, edited and organized by its community of users, at quora.com. The questions are not mine.