The article explores how governments determine if big projects like mines are good for society. They often use models that predict how the project will impact the economy. In this research, a mining project in Western Australia was examined in different scenarios. The study found that indicators like GDP don't always show how beneficial a project really is to the economy. Instead, factors like trading terms, profits, public support, financing costs, and taxes play a bigger role in measuring the project's true impact on economic welfare.