estimation of the instrumental variables regression (IVR) model (via SEM)
Maydeu-Olivares, A., Shi, D., & Rosseel, Y. (2019). Instrumental variables two-stage least squares (2SLS) vs. maximum likelihood structural equation modeling of causal effects in linear regression models. Structural Equation Modeling: A Multidisciplinary Journal, 26(6), 876-892. https://doi.org/10.1080/10705511.2019.1607740
See iv_example_mo.R and iv_example_sps.R for examples.