- According to Wolfram Alpha: 3,940 people are employed as political scientists (in 2007).
- According to the American Political Science Association: 17% of these people self-identify as IR scholars. (Actually, 17% of APSA members so identify; I assume this is representative of the profession overall (in the U.S.).
- According to the Teaching, Research, and International Policy (TRIP) project: 30-36% of American IR scholars focus on IPE.
- According to The TRIP project: 4,126 people teach "International Relations" in the US.*
- According to the TRIP project: 30-36% (33%) of American IR scholars focus on IPE.
*This seems a very inclusive categorization that includes many scholars political science would describe as comparative/area studies types rather than IR.