The Multi‐level Location Set Covering Model

The classical Location Set Covering Problem involves finding the smallest number of facilities and their locations so that each demand is covered by at least one facility. It was first introduced by Toregas in 1970. This problem can represent several different application settings including the location of emergency services and the selection of conservation sites. The Location Set Covering Problem can be formulated as a 0–1 integer‐programming model. Roth (1969) and Toregas and ReVelle (1973) developed reduction approaches that can systematically eliminate redundant columns and rows as well as identify essential sites. Such approaches can often reduce a problem to a size that is considerably smaller and easily solved by linear programming using branch and bound. Extensions to the Location Set Covering Model have been proposed so that additional levels of coverage are either encouraged or required. This paper focuses on one of the extended model forms called the Multi‐level Location Set Covering Model. The reduction rules of Roth and of Toregas and ReVelle violate properties found in the multi‐level model. This paper proposes a new set of reduction rules that can be used for the multi‐level model as well as the classic single‐level model. A demonstration of these new reduction rules is presented which indicates that such problems may be subject to significant reductions in both the numbers of demands as well as sites.     

Social Movements and the Politicization of Chronic Poverty

Discussions of chronic poverty emphasize the extent to which poverty endures because of the social relationships and structures within which particular social groups are embedded. In this sense chronic poverty is a socio‐political relationship rather than a condition of assetless‐ness. Understood as such, processes of social mobilization become central to any discussion of chronic poverty because they are vehicles through which such relationships are argued over in society and potentially changed. This article explores the ways in which social movements, as one form of such mobilization, might affect chronic poverty. Four domains are discussed: influencing the underlying dynamics of the political economy of poverty; challenging dominant meanings of poverty in society; direct effects on the assets of the poor; and engaging with the state. The inherent fragilities of social movements limit these contributions, the most important of which is to destabilize taken‐for‐granted, hegemonic discourses on poverty and its reduction.