FMiller

Yes, for Harvard, this is absolutely the case. I listed some of the reasons in my previous answer -- in Harvard's case, Business Economics strictly dominates the economics program, which is why all cross-admits do Business Economics. You can ask faculty from the Economics department during visit day, which will all tell you to do Business Economics (my older sibling was in the same position as you). As for why this might be specific to Harvard, it is because Business Economics and Economics are exactly the same program, but one pays you a bigger stipend, you have no teaching duties and you get to use HBS facilities on top of the ones from GSAS. For other schools, the programs might differ, but this is definitely not the case for Harvard. Every faculty from the Economics department and grad student will tell you Business Economics > Economics at Harvard. (Business Economics is also more selective in admissions.)

Congrats on your amazing admission results! For Harvard, Biz Ec at HBS usually wins all cross-admits. Here are some reasons: For advising and the completion of the PhD, there is essentially no difference. You can have advisers exclusively from the Economics department. Regarding the prestige aspect on the job market, there has historically been no difference: What matters is your JMP and your advisors' letters (which can be Economics department only). The HBS stipend is substantially higher and does not require any teaching. So you can spend all your time on coursework and research. The HBS facilities are much nicer, especially the office you get in comparison with Littauer basement. So if the decision you have to make is between HBS Biz Ec and Harvard Econ, every insider will tell you to take Biz Ec. I hope this helps!