This paper introduces the logarithmic autoregressive conditional duration model (log-ACD model). The logarithmic version allows for more flexibilitythan the ACD model of Engel and Russel (1995), when additional variables are included in the model. We apply the log-ACD model to bid/ask prices...

Using density forecasts, we compare the predictive performance of dur ation models that have been developed fo modelling intra-day data on stock markets. Our model portfolio encompasses the auto regressive conditional duration (ACD) model, its logarithmic version (Log-ACD), the threshold...