There are two approaches within each of these categories: single equation methods and system estimation. 2SLS, 3SLS, and IT3SLS use the least-squares method; LIML and FIML use the maximum likelihood ...

Seemingly unrelated regression (SUR), also called joint generalized least squares (JGLS) or Zellner estimation, is a generalization of OLS for multi-equation systems. Like OLS, the SUR method assumes ...