It is generally agreed that prisons have several purposes, such as protecting the public, rehabilitating prisoners, and deterring future crime. One of these purposes is punishment. Gresham M. Sykes has pointed out that there are five principal ways in which prisoners are punished. These "five pains of imprisonment" are the losses of liberty, autonomy, and security, the lack of access to desirable goods and services, and the lack of heterosexual relationships. While prisons are always a contentious subject, most experts on the penal system regard these five pains as more than sufficient for the punishment of offenders. Most would argue that at least some of these pains should be mitigated or, as far as possible, removed entirely. The security of prisoners ought not to be threatened, for instance.
It is clear, therefore, that prisoners can be and are adequately punished without prohibiting them from conducting monetary transactions. Moreover, one matter which is uncontroversial is the undesirability of punishing prisoners by causing them stress after release, since this is very likely to increase the likelihood of reoffending. One such stressor is the experience of leaving prison only to find one's financial affairs in disarray. This can have an obvious effect on the former inmate's access to housing, transport, and employment opportunities, to say nothing of destroying their credit score. These matters are difficult enough in any case, due to the inmate's lack of income while in prison. It is only reasonable that the inmate should be able to mitigate the financial damage of incarceration as far as possible by conducting transactions to prepare for some measure of financial security on release.
In situations where inmates cannot conduct financial business, they may resort to trying to use a third party. This will obviously lead to corruption and may fund criminal activity when it takes place unofficially. In for-profit prisons, where the services of some sort of broker may be available, these services will often be exorbitantly priced, taking advantage of the prisoner's lack of choices and adding further punishment to the five pains of imprisonment. For these reasons, prisoners should be able to conduct financial transactions while incarcerated.