This paper considers the estimation of average autoregressive roots-near-unity in panels where the time-series have heterogenous local-to-unity parameters. The pooled estimator is shown to have a potentially severe bias and a robust median based procedure is proposed instead. This median...

We investigate the properties of Johansen's (1988, 1991) maximum eigenvalue and trace tests for cointegration under the empirically relevant situation of near-integrated variables. Using Monte Carlo techniques, we show that in a system with near-integrated variables, the probability of reaching...

I analyze the relationship between two stylized empirical facts for stock returns: Unconditional long-term mean reversion and predictability by variables such as the dividend-price ratio or the short-term interest rate. In particular, I show that if one imposes that returns satisfy long-term...

The dividend-growth based test of return predictability, proposed by Cochrane [2008, Review of Financial Studies 21, 1533-1575], is similar to a likelihood-based test of the standard return-predictability model, treating the autoregressive parameter of the dividend-price ratio as known. In...

We provide a theoretical basis for understanding the properties of compound returns. At long horizons, multiplicative compounding induces extreme positive skewness into individual stock returns, an effect primarily driven by single-period volatility. As a consequence, most individual stocks...

Using unique transactions data for individual high-frequency trading (HFT) firms in the UK equity market, we examine if the trading activity of individual HFT firms is contemporaneously and dynamically correlated with each other, and what impact this has on price efficiency. We find that HFT...

We study the theoretical implications of cointegrated stock prices on the profitability of pairs trading strategies. If stock returns are fairly weakly correlated across time, cointegration implies very high Sharpe ratios. To the extent that the theoretical Sharpe ratios are "too large," this...

I study long-short portfolio strategies formed on seven different stock characteristics representing various measures of past returns, value, and size. Each individual characteristic results in a profitable portfolio strategy, but these single-characteristic strategies are all dominated by a...

Using two newly available ultrahigh-frequency datasets, we investigate empirically how frequently one can sample certain foreign exchange and U.S. Treasury security returns without contaminating estimates of their integrated volatility with market microstructure noise. Using volatility signature...

This paper analyzes the asymptotic properties of long-horizon estimators under both the null hypothesis and an alternative of predictability. Asymptotically, under the null of no predictability, the long-run estimator is an increasing deterministic function of the short-run estimate and the...