Hi All, I'm trying to estimate some rates using a jackknife method but the rates are really small, ie 165/5000. Using the leave one out method and pseudovalues I end up getting jack knife estimates that are twice my actual point estimates. Does anyone know if this is as a result of a small rate and if there are any work arounds, I need to calculate confidence intervals. Since I really only need the variance estimate does it matter if the jack knife estimate isn't close to my point estimate, though that seems counterintuitive. Or alternatively if I'm doing something wrong.... For the above example 165/5000 the actual rate is 0.031933 but the jack knife rate is 0.064927. Thanks, Reeza K