Economics majors must take an econometrics course in the Yale department. If you feel you have covered the material in Econ 117: Introduction to Data Analysis and Econometrics in another course, speak to the professor for Econ 123: Intermediate Data Analysis and Econometrics about taking that course. Students may also fulfill the econometrics requirement with a more advanced course, such as Econ 419: Financial Time Series or Econ 420: Applied Econometrics.
Another option for meeting the econometrics requirement for those with greater math preparation is to take Econ 135 followed by Econ 136. Econ 135 requires Math 118 or 120 and Math 222 or 225. Econ 136 requires Econ 135.