A Comment on Rothschild and Stiglitz's “Increasing Risk: I. A Definition”

Rothschild and Stiglitz (R&S) were the first to define and introduce the concept of one asset being more risky than another one. Therefore, their paper is a cornerstone in the theory of risk. Nevertheless, there is an error in a construction of the mean preserving spread (MPS) in Lemma 1 of the paper. The correction of the proof of R&S is important particularly as the paper is widely taught in courses dealing with uncertainty and risk analysis. We modified R&S's MPS and show that all their conclusions are intact.Journal of Economic LiteratureClassification Number: D81.