The article develops a semiparametric estimation method for the bivariate count data regression model. We develop a series expansion approach in which dependence between count variables is introduced ...
You can use the values from the Density column of this table with PROC GCONTOUR to plot the 1, 5, 10, 50, 90, 95, and 99 percent levels of the density: proc gcontour data=o1; plot y*x=density / ...