What subjects do you have to study to become an economist?

Assuming: You are starting with a bachelor's degree You are enrolled in a doctorate program in which the required graduate courses are built in You are a highly motivated full time student receiving Excellent help from an advisor I'd say a minimum of 3 years. Understand that I earned my bachelor's degree in economics in 2.5 years which most people find impossible, so this may be an overly optomistic answer.