There has been an extensive discussion on the applicability of Poisson Pseudo Maximum Likelihood (PPML) to trade. Here, we are going to analyse again the performance of PPML but in the light of a bimodal distribution; in addition, we also explicitly account for excess zeros. Simulations are...

We propose a novel approach to model serially dependent positive-valued variables which realize a non-trivial proportion of zero outcomes. This is a typical phenomenon in financial time series observed on high frequencies, such as cumulated trading volumes or the time between potentially...

French (2011) can analytically show that the standard Anderson and van Wincoop (2003) gravity trade model is only correctly specified for disaggregate data; gravity trade model analysis should be done at product level and then estimation results should be reaggregated. If however gravity trade...

A Dynamic Hurdle Model for Zero-Inflated Count Data: With an Application to Health Care UtilizationExcess zeros are encountered in many empirical count data applications. We provide a new explanation of extra zeros, related to the underlying stochastic process that generates events. The process...

Recently gravity trade models are applied to disaggregated trade data. Here manyzeros are characteristic. In the presence of excess zeros usual Poisson Pseudo MaximumLikelihood (PPML) is still consistent, the variance covariance matrix howeveris invalid. Correct economic interpretation however...

Recently gravity trade models are applied to disaggregated trade data. Here many zeros arecharacteristic. In the presence of excess zeros usual Poisson Pseudo Maximum Likelihood(PPML) is still consistent, the variance covariance matrix however is invalid. Correcteconomic interpretation however...

A common feature of ecological datasets is their tendency to contain many zero values. Statistical inference based on such data is likely to be inefficient or wrong unless careful thought is given to how these zeros arose and how best to model them. In this paper, we propose a framework for...

Predicting abundance across a species' distribution is useful for studies of ecology and biodiversity management. Modeling of survey data in relation to environmental variables can be a powerful method for extrapolating abundances across a species' distribution and, consequently, calculating...

Excess zeros are encountered in many empirical count data applications. We provide a new explanation of extra zeros, related to the underlying stochastic process that generates events. The process has two rates, a lower rate until the first event, and a higher one thereafter. We derive the...

Hurdle and zero-in ated models are the two foremost methods used to deal with excess zeros. However, their reliance on the nonparticipation assumption is a drawback when applied to recreation demand analysis because there is not a theoretical framework convincingly explaining presence of...