I know that adding oil to pasta water doesn't keep the noodles from sticking--much better to do that after cooking. I also know that there's no need to cook pasta at a rolling boil. My question is purely that in the title, does adding oil in any way inhibit boiling over? Scientific answers please.
Not significantly. The idea behind the technique is to reduce surface tension, thus reducing bubbling. Oil isn't very good at doing this. Oil is, however, very good at coating your pasta, which can reduce the ability of the pasta to absorb the sauce. Better idea: Use a bigger pot and more than enough water to let the pasta move about freely.