The bulk of the literature investigating persistence properties of non-renewable resource prices series has focused on application of unit root tests. This paper contributes to the debate, applying a methodology which allows (1) robust detection of the presence and (if so) the number of changes,...

The framework of stationarity testing is extended to allow a generic smooth trend function estimated nonparametrically. The asymptotic behavior of the pseudo-Lagrange multiplier test is analyzed in this setting. The proposed implementation delivers a consistent test whose limiting null...