A. Colin Cameron, Tong Li, Pravin K. Trivedi and Davis M. Zimmer
"Modeling the Differences in Counted Outcomes using Bivariate Copula Models: with Application to Mismeasured Counts"
This paper makes three contributions. First, it uses copula functions to
obtain a flexible bivariate parametric model for nonnegative integer-valued
data (counts). Second, it recovers the distribution of the difference in the
two counts from a specified bivariate count distribution. Third the methods
are applied to counts that are measured with error. Specifically we model
the determinants of the difference between the self-reported number of doctor
visits (measured with error) and true number of doctor visits (also available
in the data set used).