In this paper, we study competitive markets - a market is competitive if increasing the endowment of any one buyer does not increase the equilibrium utility of any other buyer. In the Fisher setting, competitive markets contain all markets with weak gross substitutability (WGS), a property which enable efficient algorithms for equilibrium computation. We show that every uniform utility allocation (UUA) market which is competitive, is a submodular utility allocation (SUA) market. Our result provides evidence for the existence of efficient algoritheorems for the class of competitive markets.
Deeparnab Chakrabarty, Nikhil R. Devanur