A survey by Criminal Justice Institute, Inc., indicates that by January 1, 1986, 29 States had at least the possibility of a "natural life" sentence. This literally means that inmates under such a sentence would stay in prison until they die. Such a sentence has cost implications. Robert Mitchell, chairman of the Oklahoma Pardon and Parole Board, estimates that, taking into account inflation, it would cost $2 million to keep an inmate for 50 years. As fast as the "natural life" inmate population is growing, however, it still constitutes less than 4 percent of the inmate population in State prisons. Although lifers typically are among the best behaved inmates, corrections officials fear that when lifers lose any hope that they will be released, they will behave without regard to consequences. Although many lifers acknowledge that hope of release is an important aspect of giving their lives meaning, others indicate they would attempt to make their prison lives as peaceful and satisfying as possible even if they knew they would never be released. Opponents of "natural life" sentences argue not only on the basis of cost and management problems, but also on the basis of the likelihood of an inequitable use of the sentence.