Computes a Monte Carlo confidence interval (500,000 trials) for a population unstandardized or standardized indirect effect in a path model and a Sobel standard error. This function is not recommended for a standardized indirect if the standardized slopes are greater than .4 The Monte Carlo method is general in that the slope estimates and standard errors do not need to be OLS estimates with homoscedastic standard errors. For example, LAD slope estimates and their standard errors, OLS slope estimates and heteroscedastic-consistent standard errors also could be used. In models with no direct effects, distribution-free Theil-Sen slope estimates with recovered standard errors (see ci.theil) also could be used.