Hello Ahmed,

Thanks for your response. I'd definitely be interested in seeing Luqman Ahmed's intervention. 

I do get a similar impression that companies sometimes don't share enough information with the host government. That said, one way around this is to check the filings of stock-listed parent companies. Usually companies will want to show investors that their deposits are valuable, and stock-exchange rules are relatively strict as to what you can declare and what you can't. In DRC contracts for instance, additional money is due to the state-owned companies when reserves increase, so a way of checking could be systematic stock-exchange research.

My question is rather: if we have information about the estimated reserves, how do we allocate an economic value to them? What are the commonly used formula? What are the factors taken into account? Who does this?

Thanks again, Elisabeth