[NewBoston]

Originally Posted by applicant12

1. Do you need (and need a lot) of math? Like in Econ, I know that you need at least 3 Cal classes, Linear Alg, Diff equations, Real analysis (and more). Do you need those math classes to apply for a PhD in bus?

For a Finance PhD, yes. Papers like Black and Scholes (1973) and Merton (1974) are standard reading early in the program and it only gets harder from there. More recent work gets much, much more involved. In short, more math is better for Finance. Also note that a PhD in Finance is not like the BS in terms of presentation. The core concepts are the same, but you will be dealing with them in a radically different way (with lots and lots of math.)

Originally Posted by applicant12

In addition, is there any certain courses that you need to take or you need to take just enough for a major? (is there any course in the econ dept or any other dept that is required?)

Intermediate Micro/Macro + the math you mentioned is normally considered the minimum for a good program. Econometrics courses are helpful as are high level stat classes on probability theory and data analysis. Any good overview of the concepts is useful, but not required. The more specific your research interests, the easier it would be to identify classes which would provide the maximum benefit.

Originally Posted by applicant12

2. Why don't most Bus schools accept GRE instead of the GMAT?

They often do! Take both unless you know for sure the programs you are applying to will only use the GMAT. Stanford GSB only takes the GRE for Finance PhD applicants.

Originally Posted by applicant12

3. Correct me if I'm wrong but I think I've seen PhDs in econ teach courses in Bus school but I don't think I've seen people with PhD in finance or any other aspect of business teach in an Econ Dept. Is it because of the nature of the science or what?

Once upon a time, not long ago, there were few if any Finance PhD programs. That has now changed. The rise of the Finance PhD has led to the reduction if not outright elimination at most schools of hiring an Econ PhD to teach in the Business School. One reason is the Finance PhDs will learn (and master) a huge range of Finance topics from Corp. Finance to Asset Pricing while Econ PhDs often do some more narrow subset of the Finance literature in addition to, say, macro and/or metrics. It still happens, but nowhere near as frequently and often only due to taking someone from a much higher ranked program. For example, a Harvard Econ PhD may end up teaching Finance at a top 25-50 business school. But it is much more rare for a non-top 10ish Econ PhD to have the same opportunity coming from an Econ PhD.