Simulated models suffer intrinsically from validation and comparison problems. The choice of a suitable indicator quantifying the distance between the model and the data is pivotal to model selection. However, how to validate and discriminate between alternative models is still an open problem...

In this paper, we review the recent econometric methods related to unit root tests. The central idea is the interaction between structural breaks and unit roots. We consider the standard Dickey-Fuller test and its modifications that allow under the alternative hypothesis one or multiple...

This note is concerned with two recent agent-based models of speculative dynamics from the literature, one by Gaunersdorfer and Hommes and the other by He and Li. At short as well as long lags, both of them display an autocorrelation structure in absolute and squared returns that comes...