In a concurrence to a per curiam opinion affirming a District Court’s imposition of a life sentence, Judge Posner laid down some social cost calculus, assessing how expensive it is to lock someone up for life–both in terms of how much it costs to incarcerate them, but also the prisoner’s inability to contribute taxpayer dollars to pay for that care.

I write separately merely to remind the district judges of this circuit of the importance of careful consideration of the wisdom of imposing de facto life sentences . . . .

Federal imprisonment is expensive to the government; the average expense of maintaining a federal prisoner for a year is between $25,000 and $30,000, Notice, Bureau of Prisons, 76 Fed. Reg. 57081 (Sept. 15, 2011), www.gpo.gov/fdsys/pkg/FR-20 11 -09-15/pdf/2011- 23618.pdf, and the expense rises steeply with the prisoner’s age because the medical component of a prisoner’s expense will rise with his age, especially if he is still alive in his 70s (not to mention his 80s or 90s). It has been estimated that an elderly prisoner costs the prison system between $60,000 and $70,000 a year. Kelly Porcella, Note, “The Past Coming Back to Haunt Them: The Prosecution and Sentencing of Once Deadly But Now Elderly Criminals,” 81 St. John’s L. Rev. 369, 383 (2007).

That is not a net social cost, because if free these elderly prisoners would in all likelihood receive Medicare and maybe Medicaid benefits to cover their medical expenses. But if freed before they became elderly, and employed, they would have contributed to the Medicare and Medicaid programs through payroll taxes—which is a reminder of an additional social cost of imprisonment: the loss of whatever income the prisoner might lawfully have earned had he been free, income reflecting his contribution to society through lawful employment. The social costs of imprisonment should in principle be compared with the benefits of imprisonment to the society, consisting mainly of deterrence and incapacitation.

A sentencing judge should therefore consider the incremental deterrent and incapacitative effects of a very long sentence compared to a somewhat shorter one. An impressive body of economic research (summarized and extended in David S. Abrams, “The Imprisoner’s Dilemma: A Cost Benefit Approach to Incarceration,” forthcoming in Iowa Law Review) finds for example that forgoing imprisonment as punishment of criminals whose crimes inflict little harm may save more in costs of imprisonment than the cost in increased crime that it creates. Ours is not a “little crime” case, and not even the defendant suggests that probation would be an appropriate punishment. But it is a lifetime imprisonment case, and the implications for cost, incapacitation, and deterrence create grounds for questioning that length of sentence.