I am interested in understanding the algorithm/methodology of the WGI (the most cited and popular corruption/governance) World Bank Methodology. They try to publish as detailed as possible to the public but I struggle to figure out how they manage to solve the maximisation at page 97-99 here Governance Matters VII: Aggregate and Individual Governance Indicators, 1996-2007
Basically, they end up with a maximum-likehood estimation with three unknown parameters and state that it is a standard estimation. I am not an expert in Stata/Mata/Mathlab but honestly I can't see the trivial point.
Can anyone help and refer me to some statistical packages?