Yvan Lengwiler (1998). Journal of Mathematical Economics 30 (1), 37-58.
This paper deals with atomless exchange economies which do not fulfill the usual autarky assumption, meaning the endowments may lie outside the consumption set. I establish the existence of a Walras equilibrium, provided the economy is ‘heterogenous’ (in some precise sense). Furthermore, the First Welfare Theorem is generalized to arbitrary, not necessarily autarkic economies.