Business improvement districts (BIDs) have become a ubiquitous feature of the urban development toolkit. An important — perhaps the most important — instantiation of the trend in urban governance toward the devolution of local authority to new "sublocal," quasi-governmental institutions, BIDs play an important role in urban re-development efforts, especially efforts to revitalize downtowns and satellite center-city business districts. It would be difficult to disentangle the remarkable resurgence of Center City, Philadelphia, for example, from the rise of the Center City District, a BID that spends millions of dollars each year on a wide range of public services, including sanitation, street beautification, capital improvements, business promotion, supplementary security, and even the operation of a community court. Despite (or perhaps because of) the apparent successes of high-profile BIDs like the Center City District, BIDs remain controversial, with some commentators praising them as an ingenious way to overcome the collective action problems that prevent neighbors from voluntarily organizing to address community problems and others condemning them as dangerously anti-democratic and privatizing.