My mission is to explore the issues of poverty and social exclusion across the boundary between developed and developing countries. Put briskly, the thesis is that increasing attention to poverty and social exclusion (PSE) in the North opens the possibility of fertile dialogue between North and South, on three questions of successively greater depth. First, are there new comparisons, or lessons to be drawn across geographical boundaries, about the characteristics, causes and remedies of PSE? Second, does the rapid increase in PSE in the North signal a new convergence between North and South? And third, are there theories to hand which will expose connections between PSE in North and South? The thesis is that the answer to each of these questions is 'yes': there are then exciting possibilities for a new 'mono-economics'2, in which the boundaries of development studies begin to dissolve. Perhaps the Third World really is no more than a 'collective psychological delusion' Or does globalisation now mean that we are all developing countries?