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...

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...

In regressions involving integrable functions we examine the limit properties of IV estimators that utilise integrable transformations of lagged regressors as instruments. The regressors can be either I(0) or nearly integrated (NI) processes. We show that this kind of nonlinearity in the...