The fund size is highly persistent and correlated with risk factor loadings. Hence, it is unrealistic to assume constant diseconomies of scale over a long time. The traditional two-step method underestimates the uncertainty of diseconomies of scale. We propose a one-step procedure with a random...

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...

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...

When using daily mutual fund returns to study market timing ability, heavy tails and heteroscedasticity significantly challenge the existing methods. We propose a weighted nonparametric measure and test for market timing. The test finds that the traditional parametric inference misclassifies...