There is virtually a consensus that the ratio of suicides committed with guns to total suicides is the best way to indirectly measure gun ownership across different locations. However, such a proxy is not accurate for any locality with low population density in view that suicides are rare...

This paper develops a family of autoregressive conditional duration (ACD) models that encompasses most specifications in the literature. The nesting relies on a Box-Cox transformation with shape parameter [delta] to the conditional duration process anda possibly asymmetric shocks impact curve....