existing lack of integration in Europe may not be a result of missing institutional reforms. In the Poisson estimations, the …

existing lack of integration in Europe may not be a result of missing institutional reforms. In the Poisson estimations, the …

to this development, as zero-inflated Poisson or zero-inflated Negative Binomial Maximum Likelihood estimators are not … robust to misspecification. In contrast, simple Poisson regression provides consistent parameter estimates even in the … presence of excess zeros. The advantages of the Poisson approach are illustrated in a series of Monte Carlo simulations. …