Everybody has the innate need to have something to do or work upon in their lives that provides them with some sort of satisfaction in the accomplishing of those given things. For many of us, we work, not just because it is a means to procure income, but because we get the satisfaction of accomplishing something of real merit, each and every day that we work. For others, that may not have or desire a paying job, there is satisfaction, for example, in taking care of household tasks and the bringing up and mentoring of children, or in volunteer work, or in various hobbies and activities, that fulfill us. In all of this, the general commonality is that our self-worth is caught up in the positive activities that we engage in day-by-day.
On the other hand, there are plenty of people, that are unemployed, or apparently unemployable because they lack the right skill set or have mental or physical limitations, or job opportunities are not readily available in their area, or the pay is too paltry, or the conditions of the work are denigrating or dangerous, so that the end result is that they have little hope of gainful employment and thus remain unemployed. So too, there are people, though being employed, are employed in dead end jobs that they get little or no satisfaction from in the work so being done, which is often coupled with remunerative pay which is insultingly low and thereby not enough to make a sustainable living from.
In those cases, of people who are unemployed, or are frustrated within their employment or the conditions of that employment; that disappointment, as well as often having extra time on their hands, without much of value to accomplish, often lends itself to ill advised or destructive behavior, typically directed against one's own self with things such as substance abuse or pernicious addictions, while also having a strong tendency to strike out against society, at large, in some way. Those that have nothing, and do not believe that they will ever have anything, are prone to antisocial behavior of all sorts, because their perception of who and what they are, is very low, and without a belief that they are of any real worth, will often deal with such by striking back against that which they perceive has taken their self-worth from them.
So then, there is a strong correlation between crime and unemployment, as well as crime so caused by perceived unfairness. After all, those that have nothing much to do, and nothing of intrinsic value in their possession, and do not have the ready means to change such are going to have a strong tendency to take what they can take, not only because they have a need for such, but because their anger overrules any innate sensibility that they might have.
One of the things about employment is that those employed devote a meaningful amount of time each day in the accomplishment of their work duties; of which, on the other hand, those that are not employed and are not going to school, and have little home responsibility, do not. This signifies that idle hands, and idle minds, need to fill the vacuum that the lack of employment leaves them, and those that believe that they have little or no value to society because they are not contributing to that society, are going to, more times than not, engage in behavior that is destructive to themselves as well as to that society.