Monte Carlo Confidence Intervals for Complex Functions of Indirect Effects
One challenge in mediation analysis is to generate a confidence interval (CI) with high coverage and power that maintains a nominal significance level for any well defined function of indirect and direct effects in the general context of structural equation modeling (SEM) This study discusses a proposed Monte Carlo extension that finds the CIs for any well defined function of the coefficients of SEM such as the product of k coefficients and the ratio of the contrasts of indirect effects, using the Monte Carlo method. Finally, we conduct a small scale simulation study to compare CIs produced by the Monte Carlo, nonparametric bootstrap, and asymptotic delta methods. Based on our simulation study, we recommend researchers use the Monte Carlo method to test a complex function of indirect effects.