A Note on Two Notions of Arbitrage

Since Hart's [5] and Werner's [10] seminal papers, several conditions have been proposed to show the existence of equilibrium in an asset exchange economy with short-selling. In this note, we discuss the relationship between two no-arbitrage conditions. The ̄rst condition is the assumption that the individually rational utility set U is compact, as considered by Dana, Le Van and Magnien [1]. The second is inconsequential arbitrage, introduced by Page, Wooders and Monteiro [9]. The main result of this comparison is to show that the inconsequential arbitrage condition is stronger than the assumption that U is compact.