MLE in causalmed

[zartash]

why does SAS causalmed uses maximum likelihood estimation for model parameters. Is this based on some studies. please provide references

[PGStats]

 SAS provides 13 references. Are you looking for references not provided in the procedure documentation?

https://documentation.sas.com/?docsetId=statug&docsetVersion=14.3&docsetTarget=statug_causalmed_refe... 

[zartash]

I want to ask why SAS use maximum likelihood for model estimation. Why not
OLS. Or any other technique. I need reference for using maximum likelihood
estimation in causal mediation analysis.