Stochastic simulation results. Fraction of infected farms vs. fraction of farms which have been clear for at least 5 years for a sample of stochastic simulations. Simulation parameters are selected from their prior distributions. Fractional values are calculated for a different random set of 301 farms for each simulation. The black circle shows the result of the Scottish BVD herd prevalence study. Only members of the prior distributions of parameters producing results sufficiently close to the observed value (see text for details) are chosen as members of the posterior distribution.