Diversity jurisdiction depends on the citizenship of the parties, not their residences, office addresses or where they conduct business. Although this issue is taught in law school, experienced lawyers sometimes forget to allege the citizenship of the various parties. I will admit that I have even made this mistake in my career. Here the district judge was merciful and allowed the plaintiff to amend the complaint to allege citizenship, not residency or an office address. As the court correctly noted, residency is not enough. Citizenship is the same as domicile.
It is remarkable how many cases are dismissed every year by the federal courts for lack of diversity jurisdiction. You would think we lawyers would have learned by now.
Edward X. Clinton, Jr.