  Needs have long played a role as guides to public policy, not only domestically but also internationally, where the so-called Basic Needs Approach to global poverty and international development became dominant in the 1970s and early 1980s. More recently, however, it has been displaced by the ‘capabilities approach’ developed especially by Amartya Sen and implemented in policy instruments such as the UN’s Human Development Index. Sen (1984) argued that the basic needs approach was too narrow for these purposes, as well as being defective for a number of other reasons, and should therefore be subsumed within his capabilities approach. In this section we review the arguments for and against replacing needs with capabilities as a tool of policy evaluation (see also Reader 2006). For a much fuller discussion of capabilities themselves,  see the entry on  the capability approach.  