Sahiwal bulls have been bred at the National Sahiwal Stud (NSS) in Naivasha since the late 1960s. The breed is credited for its ability to withstand conditions which other introduced cattle breeds find it difficult, especially those in the ASALs. The sahiwal will produce milk with little...

By discriminating between a lazy manager and a career concerns hypothesis, Aghion et al. (The American Economic Review 2013, 103(1), 277-304) try to disentangle the link between innovation and institutional ownership. Citation-weighted patent counts are used as a proxy for innovation, which...

In 2004, the German Social Health Insurance introduced a co-payment for the first doctor visit in a calendar quarter. I combine a structural model of health care demand and a difference-in-differences strategy to estimate the effect of that reform on the number of visits. In the model, the...

We present motivation and new commands for modeling count data. While our focus is to present new commands for estimating count data, we also discuss generalized binomial regression and present the zero-inflated versions of each model. Copyright 2014 by StataCorp LP.

In this paper we consider a Bayesian approach for the zero-modified Poisson distribution, which is recommended for fitting count data which shows any modification related to the frequency of zero. However, some loss may occur when we have the knowledge that the datasets show no modification in...

In this paper, we examine heterogeneity in the trip preferences of recreationists by applying a random parameters negative binomial model and a latent class negative binomial model to a panel data set of beach users at a site on the west coast of Ireland. This is the first such attempt in the...

Health disparities are abundantly recorded in literature, but is much less understood within a rural-urban context. In this paper, four major diseases in Virginia are studied: cancer, stroke, cardiovascular disease (heart disease) and chronic obstructive pulmonary disease (COPD). Separate count...

In response to increasing health expenditures and a high number of physician visits, the German government introduced a copayment for ambulatory care in 2004 for individuals with statutory health insurance (SHI). Because persons with private insurance were exempt from the copayments, this...

The current study contributes to the already substantial scholarly literature on telecommuting by estimating a joint model of three dimensions—option, choice and frequency of telecommuting. In doing so, we focus on workers who are not self-employed workers and who have a primary work place...