This paper explores some properties of periodically collapsing bubbles, which are a very popular model in the bubbles literature. We first demonstrate that complicated nonlinear bubbles can be represented as a time-varying parameter linear model of order 1. We demonstrate that the bubbles are...

This paper shows that the recently proposed tests of linear and logarithmic transformations for integrated processes against each other by Kobayashi and McAleer (1999) are severely biased for alternative hypotheses when the true data generating process is a stochastic unit root. An empirical...