The European Union (EU) has more preferential trading arrangements than any other trading entity. For a quarter of a century African, Caribbean and Pacific (ACP) countries have benefited from unreciprocated preferential access to the EU market under a succession of Lomé Arrangements. Sunset provisions now apply to these concessions and after 2007 unreciprocated preferences will end. The EU is proposing that a network of regional Economic Partnership Agreements (REPAs) replace Lomé. This is a new form of regional trading arrangement for both the EU and ACP countries. In this paper we develop an analytical framework for evaluating the impact effects of a REPA and apply this to estimate costs and benefits in the CARICOM region. Our results suggest that a REPA would be inferior on welfare grounds to either extended reciprocity with the EU and US, or broader multilateral liberalisation.