Edwin J. Elton and Martin J. Gruber are Professors Emeritus and Scholars in Residence at NYU Stern School of Business, and Andre de Souza is Assistant Professor of Finance and Economics at St. John’s University Peter J. Tobin College of Business. This post is based on their recent paper.
Over 25% of the assets held by investment companies are held in the form of passive index funds and passive exchange traded funds. Furthermore, many indexes are followed by multiple passive funds. Empirical evidence shows that active funds underperform indexes by about 75 basis points. Given these facts, it is important for investors to understand how to make the choice among and between index funds and ETFs for any particular index. The purpose of this paper is to explain what affects performance and how to choose between passive vehicles.
In the first part of the paper, we examine return pre-expenses which measures management’s performance. Managers closely follow their index resulting in an average R2 above .996 and an average beta of 1 for ETFs and .998 for index funds. On average, ETFs pre-expenses slightly outperform the index they follow, while index funds slightly underperform.