Macroeconomic time series often involve a threshold effect in theirARMA representation, and exhibit long memory features. In this paperwe introduce a new class of threshold ARFIMA models to account forthis. The threshold effect is introduced in the autoregressive and/or thefractional integration...

This paper investigates some common determinants of default probability changes ofindividual firms using Standard & Poor's ratings database. We analyze and quantify the re-sponses of hazard rates to changes in various economic variables, namely financial markets,business cycle and credit...

We develop an econometric methodology to infer the path of risk premia from large unbalancedpanel of individual stock returns. We estimate the time-varying risk premia implied by conditional linearasset pricing models where the conditioning includes instruments common to all assets and asset...

We derive nonparametric tests of symmetry using asymmetric kernels with either shrinkingor fixed bandwidths. We show how to extend the approach to examine conditional symmetry byderiving conditions under which our tests are applicable to residuals from semiparametric modelswith a (sufficiently...

We propose a technique to avoid spurious detections of jumps in highfrequencydata via an explicit thresholding on available test statistics. Weprove that it eliminates asymptotically all spurious detections. MonteCarlo results show that it performs also well in finite samples. In DowJones...

We study the robustness of block resampling procedures for time series. We first derive a setof formulas to quantify their quantile breakdown point. For the block bootstrap and the sub-sampling, we find a very low quantile breakdown point. A similar robustness problem arisesin relation to...