Q:

Is there any unwritten rule against hiring already unemployed PhDs?

I have seen several articles in internet about a general bias against hiring long term unemployed people in non-necessarily academic jobs, see for example here and here. I was wondering if there is such an unwritten rule in academia as well? 
I am sure someone might say it is not the case and according to the rules X and Y, it is considered a discrimination and it is forbidden by law and so on. I am not asking what the written laws say. I would like to know if there is such a bias in hiring committees or not? And if there is such a thing how can a long term unemployed academic do to overcome this obstacle? 

A:

I don't think there is an unwritten rule, precisely, but I think once you are not employed in academia (even if you have a job somewhere else), your chances of getting a position in academia decrease extremely rapidly.  Competition for positions is so massive, and there are so many well qualified applicants that I think someone who is not currently in an academic or research position is unlikely to be taken seriously.  Not to mention that you typically aren't doing the kind of research and networking you need to get a position if you are unemployed (not always, but often).  I think some fields where it's very hard to get work are a bit more forgiving (though, of course there there is even more competition), but this is part of what keeps people in adjunct positions, since it is a way of staying "in the game."

A:

In any case (academic or not), you always have to account for any hole on your CV. The main idea here is that someone always loses skills when he doesn't have any activity.
However, holes in CV can have many different root causes (disease, looking for a job in a country struck by the economic crisis, humanitarian work, taking care of children at home...). It is usually best to either write it down explicitly (disease for example) or to turn it into some positive, meaningful experience (humanitarian work, etc.). For example, someone who took care of children at home can have learned some organization skills, done some scientific blogging or contributed to some scientific tool on spare time. 
This will not always be accepted by a recruiter, but it's better than holes in the CV that just raise suspicion about one's commitment. 

