This paper shows how truncated censored hurdle zero in ated and underreported count models can be interpreted as models with selectivity Until recently such count data models have commonly imposed independence between the count generating mechanism and the selection mechanism Such an assumption is unrealistic in most applications and various models with endogenous selectivity correlation betwee...

Poisson regression has been widely used to model count data. However, it is often criticized for its restrictive assumption of equi-dispersion, meaning equality between the variance and the mean. In real-life applications, count data often exhibits over-dispersion and excess zeroes. While Negative binomial regression is able to model count data with over-dispersion, both Hurdle (Mullahy, 1986) ...

Often, economic policies are directed toward outcomes that are measured as counts. Examples of economic variables that use a basic counting scale are number of children as an indicator of fertility, number of doctor visits as an indicator of health care demand, and number of days absent from work as an indicator of employee shirking. Several econometric methods are available for analyzing such ...