Unit root tests in three‐regime SETAR models

Unit Root Tests in Three-Regime SETAR Models

This paper proposes a simple direct testing procedure to distinguish a linear unit root process from a globally stationary three-regime self-exciting threshold autoregressive process. We derive the asymptotic null distribution of the Wald statistic, and show that it does not depend on unknown fixed threshold values. Monte Carlo evidence clearly indicates that the exponential average of the Wald...

Bootstrap Unit Root Tests

We consider the bootstrap unit root tests based on finite order autoregressive integrated models driven by iid innovations, with or without deterministic time trends. A general methodology is developed to approximate asymptotic distributions for the models driven by integrated time series, and used to obtain asymptotic expansions for the Dickey–Fuller unit root tests. The second-order terms in ...

Differencing and Unit Root Tests

e d In the Box-Jenkins approach to analyzing time series, a key question is whether to difference th ata, i.e., to replace the raw data {y } by the differenced series {y −y }. Experience indicates that m t t t −1 ost economic time series tend to wander and are not stationary, but that differencing often yields a e r stationary result. A key example, which often provides a fairly good descriptio...

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