Public Safety through Private Action: An Economic Assessment of BIDS
研究了商业改善区（BID）通过私人支出提升公共安全的效果，发现其社会收益约为私人支出的20倍，且犯罪转移效应极小，同时逮捕率下降，表明额外节省。
Private actions to avoid and prevent criminal victimisation and assist public law enforcement are vital inputs into the crime‐control process. One form of private action, the business improvement district (BID), appears particularly promising. A BID is a non‐profit organisation created by property owners to provide local public goods, usually including public safety. Our analysis of 30 Los Angeles BIDs demonstrates that the social benefits of BID expenditures on security are a large multiple (about 20) of the private expenditures. Crime displacement appears minimal. Crime reduction in the BID areas has been accompanied by a reduction in arrests, suggesting further savings.