The Poverty-Environment Initiative (PEI) of the United Nations Development Programme (UNDP) and the United Nations Environment Programme (UNEP) is a global UN effort that supports country-led efforts to mainstream poverty-environment linkages into national development planning. The PEI provides financial and technical assist-ance to government partners to set up institutional and capacity-strengthening programmes and carry out activities to address the particular poverty-environment context. Making the Economic Case: A Primer on the Economic Arguments for Mainstreaming Poverty-Environment Linkages into Development Planning is also available online at www.unpei.org. Second edition. Published 2009. © 2008 UNDP-UNE