Hi all, I am a retail and economic geographer and I'm wrapping up my PhD applications for next Fall. I didn't apply to many programs, but the ones I'm applying to are really really disparate:

Applied Economics PhD - Missouri
Geography PhD - Toronto
Business PhD - Dublin

Obviously, quantitative economic geography is a pretty niched and tiny field that sits at an intersection of some broader fields. I picked these programs because the advisors were doing work that fit my interests well in spite of the fact that they all teach in different departments and reside in different academic/professional ecosystems. The differences in these programs culturally, academically and professionally have me worried about how I'm branding myself. Do I want to be perceived as an economist, a geographer or a business scholar? Has anyone else been in this situation? Did you find yourself with prospective advisors that were all great fits that all came from very different worlds? What due dilligence do you recommend here so I can make the most informed decision if I'm accepted? I'm guessing visiting these places is really the safest bet. Any input is so appreciated!

Visiting each of the three is a good idea but it won't help you decide what you want to be known for in years to come when you are no longer at these institutes.

Only you can make this decision based on what you really want.

Do you really need to make the decision now or can you find a way of bringing your disparate interests together in a single piece of work under one of these supervisors?

The PhD systems are massively different between Ireland and the USA (don't know about Canada). 3 vs 7 years is a big difference and I think that is something you should really consider. Also the scholarships/teaching requirements may differ a lot and you should consider them before choosing.

Though I understand your question about being perceived differently depending on your home department. I am on the boundary of chemistry and mechanical engineering with a bit of bioscience. Depending on the conference, I am the random chemist or pessimistic engineer but people will still listen to me. I feel am in both fields despite being in the Mechanical Engineering department, I just tailor my output for the audience. Academic fields are inherently diverse and multi-skilled and it is possible to change fields in your later career (though can be hard). If you are worried about being shoe-horned into a way of thinking, get a diverse supervisory team. See if you can get three supervisors in the three fields so that you get a bit of everything. Hope that helps.