The biggest question in my mind when reading this article is "how are the relative costs and values actually being calculated?" How can we say that $1.00 spent

The biggest question in my mind when reading this article is "how are the relative costs and values actually being calculated?" How can we say that $1.00 spent on clean energy will bring $11.00 in benefits, when $1.00 on counter-terrorism will bring $0.30 in benefits? How much of it is speculation? In other words, what was the method for quantifying the amount of benefit that we see from the investment?