This study provides a critical assessment of long-horizon return predictability tests using highly persistent regressors. We show that the most commonly used test statistics are typically oversized, leading to spurious inference. As a remedy, we propose a simple Wald statistic, which can...

This study examines stock return predictability via lagged financial variables with unknown stochastic properties. We conduct a battery of predictability tests for US stock returns during the 1927-2012 period, proposing a novel testing procedure which: i) robustifies inference to the degree of...

A limit theory is developed for mildly explosive autoregressions under stationary (weakly or strongly dependent) conditionally heteroskedastic errors. The conditional variance process is allowed to be stationary, integrable and mixingale, thus encompassing general classes of GARCH type or...

Nielsen (Working paper, University of Oxford, 2009) shows that vector autoregression is inconsistent when there are common explosive roots with geometric multiplicity greater than unity. This paper discusses that result, provides a coexplosive system extension and an illustrative example that...