In this paper we show that in a pure exchange economy it is possible to improve the social welfare along an e±cient path. This path will be called the Negishi map. Moving the relative weights of the agent in a social welfare utility function, we obtain an e±cient path of allocations and social...

In this paper we show that in a pure exchange economy where social weights and total resources are fixed there is no possibility to improve the social welfare by means of efficient reallocations of the resources. However, if social weights are not fixed but can be selected from a particular set,...