The article uses a model to study how mineral policies affect Nigeria's economy. The model is like a big economic simulator that shows how different parts of the economy interact. It looks at things like how businesses, people, and markets affect each other. The researchers used a specific type of model called the PEP 1-1 Single Country Model. They found that this model is good at predicting how policies impact the economy. By using this model, they figured out the effects of changing mineral policies on Nigeria's economy.