For Americans behind bars, connections to the outside world are scarce: There are letters that come in and out, occasional visits from lawyers and family members, and, besides that, there is the prison payphone.

But the calls don't come cheap: Families -- who accept the calls collect -- can pay rates up to 24 times as much as a normal call, sometimes as much as $20 for just 15 minutes, though the charges vary wildly state to state. In Maryland, for example, placing a call can cost $2.55 for the first minute, and each additional minute will ring up another 30 cents (and due to dropped calls, sometimes prisoners can end up paying for that costly first minute multiple times in one conversation). The high charges are at least partly the result of commissions states can charge service providers for operating the phones -- a cost shifted to the prison population (literally a captive market) and their families. Maryland collected $5.2 million from such commissions in 2010.

And the burden likely extends beyond prisoners and their families: Increased contact with family is thought to be a significant factor in easing re-entry to post-prison life and reducing recidivism over the long haul. Abig study recently found that prisoners who were visited were 13 percent less likely to be convicted of a felony upon release and 25 percent less likely to end up back in prison for a technical violation. But the study didn't look to see whether phone calls could have a similar effect because, quote, "they are prohibitively expensive."

Read more at The Atlantic.