Trevor S. answered 03/23/19
Experienced English Tutor Specializing in Essay Help and SAT prep
Great question! Em dashes are tricky--partially because they act as "wildcards" in a sense. Whatever is set off by the dashes (in this case, "lack of education, poverty, unemployment") does not need to express a complete thought. Read your sentence without the dahses (and their contained words). Does it make sense? If not, you are not using the dashes correctly. In your example, dashes are used well! You can think of dashes as a self-interruption. You make your quick announcement, then return to the regularly-schedule program.
You do not have to put "and" between the second and final items of the list because em dashes are, as I said before, wildcards. The flow of the sentence is clear without that conjunction, so it is not necesary.
-- Trevor Smith.