1. used a contingent valuation study to examine consumers' preferences for a world heritage site in Japan. The ordered probit study follows a Vote/No Vote choice, and so has elements of the semiordered bivariate probit model described earlier as well. In two very natural application, Kohler and Rodgers (1999) studied the motivation to have children in a survey of pairs of twins;See;However, the bivariate Poisson regession model remains to be well developed,1995