There is a widespread belief among economists that adding additional variables to a regression model causes higher standard errors. This note shows that, in general, this belief is unfounded and that the impact of adding variables on coefficients’ standard errors is unclear. The concept of...

Ambiguity surrounds any importance measure in cases in which predictor variables are correlated. However, a new measure is proposed that has attractive properties, such as providing individual contributions that are both non-negative and sum to R2. The new measure is compared with four other...

This empirical study investigates the ability of exchange-traded funds (ETFs) to replicate the risk-return characteristics of their respective benchmarks accurately. By decomposing ex-post tracking performance, this study finds that the commonly used measure, tracking error, rarely sufficiently...