Weak form efficiency of stock markets implies unpredictability of stock returns in a time series sense, and the latter is tested predominantly under a serial independence or martingale difference assumption. Since these properties rule out weak dependence that may exist in stock returns, it is...

This paper analyzes the implications of cross-sectional heteroskedasticity in repeat sales regression (RSR). RSR estimators are essentially geometric averages of individual asset returns because of the logarithmic transformation of price relatives. We show that the cross sectional variance of...

In studies of time series momentum (TSM), the Newey-West t-test has size distortion for linear predictive regression with excess returns because of non-stationarity, endogeneity due to correlated errors, and a lack of finite moments due to heavy tails. To solve these problems, we propose a new...

I compare the performance of the index-based time series approach and the cross-sectional approach in estimating factor loadings of non-traded assets, and show that the latter likely provides less biased and more efficient estimates. I then use the cross-sectional approach to estimate the...

This paper analyzes the implications of cross-sectional heteroskedasticity in repeat sales regression (RSR). RSR estimators are essentially geometric averages of individual asset returns because of the logarithmic transformation of price relatives. We show that the cross sectional variance of...

When using daily mutual fund returns to study the market timing, heavy tails and heteroscedasticity significantly challenge the existing methods. We to accommodate them, we propose a new measure and an efficient test for market timing ability and find that the traditional test misclassifies...

We show that two prominent bootstrap tests for fund skill have distorted test sizes because many funds have short return records and skewed return residuals, and they lack test power to detect skilled funds when a substantial number of unskilled funds are present. We develop the theory for a...