is the first difference the log first difference in regression? vs log first difference in regression can you use the first difference and log first difference? what is the first difference why log first difference does the first difference mean the log first difference or log first difference can you calculate covariances from log first difference what is the relationship between first difference and log first difference why is the log first difference used for the covariance which is better first difference or log first difference i am evaluating the effect of covariances between regressions between series on returns. when do you use first difference and log first difference in regression what is the difference of first and log first difference what is the difference between first difference and log first difference what is the log first difference first difference or log why use log first difference and first difference for regression analysis can you use log first difference as the covariate? how to use log first difference and first difference what is a first difference regression