According to the fbi bank crime statistics, there were more than 4,000 bank robberies in the united states in 2015, an increase of 3.9 percent over 2014. the fbi claims that banks have made themselves easy targets by refusing to install clear acrylic partitions, called bandit barriers, that separate bank tellers from the public. according to a special agent with the fbi, "bandit barriers are a great deterrent. we've talked to guys who rob banks, and as soon as they see a bandit barrier, they go find another bank." sources: u. s. department of justice, federal bureau of investigation, "bank crime statistics 2015," and "bank crime statistics 2014"; and richard cowen, "fbi: banks are to blame for rise in robberies," northjersey, march 10, 2009. despite this finding, many banks have been reluctant to install these barriers. wouldn't banks have a strong incentive to install bandit barriers to deter robberies? why, then, do so many banks not do so?