In 2019, U.S. pharmaceutical companies paid $3.6 billion to physicians in the form of gifts to promote their drugs. The practice of offering financial incentives has raised concerns about potential conflict of interest. To curb such inappropriate financial relationships between healthcare...

Multivariate count models represent a natural way of accommodating data from multiple product categories when the dependent variable in each category is represented by a positive integer. In this paper, we propose a new simultaneous equation multi-category count data model ndash; the...