Delta method for a ratio
Posted: Mon May 28, 2018 5:12 pm
I would like to calculate the variance for a ratio. The ratio is Ne/Nc (i.e., genetic effective population size/census population size). I estimated Ne using a genetics software (NeEstimator) and I estimated “Nc” (i.e., abundance) using Program MARK. I believe the best way to approximate a variance for this ratio is using the Delta method. However, I do not believe that these parameters are independent, which means I need the covariance (in addition to each estimate’s variance) to approximate a variance for the ratio. Because these estimates are not generated using the same software, I do not have a variance-covariance matrix. Does anyone have any suggestions for obtaining a covariance for two parameters estimated using different software programs or any other suggestions for obtaining a variance for this ratio? Any suggestions would be greatly appreciated! Thank you!