Hi,
I would think a focus on econometrics courses is well advised, but keep in mind that there is a difference between econ PhD and business PhD. If the courses focus on a lot of rigorous mathematical concerns, like proof, your time might be better spent elsewhere.
Also, business research can be carried out in many ways. Some departments are very "sociology" oriented than "econ" oriented. Your preparation efforts should reflect the departments you are or plan on heading.
As someone with IS exposure, I'd also caution an overt emphasis on econometrics for IS research. There is a growing concern among IS scholars that the research conducted in IS community lacks relevance. That is to say, all this nice regression research, based on positivist philosophy, just doesn't help giving managerial insights to MIS practitioners. I am one big proponent for such an opinion. It is sad to see doctoral students in IS slaving away to do all those econometrics-based research to shoot for MISQ/ISR publication, and then learn some half-baked skills in system analysis and design just to fulfill the teaching duty. The result is bad teaching and bad learning. I think you are better prepared if you know what kind of IS you are interested in spending the rest of your life doing first. Is it the purely managerial oriented IS that is much like strategy? If so, yes, econometrics will be your best tool. But if you hope to become a scholar capable of guiding technical professional, then that might be the wrong way to go. This is probably a symptom of deeper issues in IS as a field. IS is actually more like two disciplines forced to join together, and might actually be better served if they go their separate ways (in many regard, they already have. publishing in different set of journals, going to different departments, hosting different conferences, etc). For more IS related info, you can go to
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