When the Census Bureau counts prisoners, they are tallied at their prison addresses because that is their usual residence under census rules. Some government officials and advocates have urged the Census Bureau to count prisoners at their home addresses, arguing that counting them in prisons gives disproportionate power to the areas (often rural) where those facilities are located. This week, the Census Bureau agreed to give states more power to address this issue themselves when 2010 Census numbers come out.
Census population totals are used to draw the boundaries of state legislative districts or other voting districts, which by law must be of equal size. To illustrate the outsize power that some prison communities have, one advocacy group cites the example of Anamosa, Iowa, where counting the non-voting inmates in a prison gave the 56 people living in the ward where it was located effectively as much influence as the 1,374 people living in each of the other wards. The city later abolished the prison district. An evaluation of census residence rules in 2006 by the National Research Council (part of the National Academy of Sciences) said the evidence is "compelling" that political inequities result from current practice.
Read the full commentary The Prisoner Dilemma on the Pew Research Center's Web site.