I'm just curious as to what Luke is referring to here. Is he referring to "the world" or "the inhabited land" as the whole Roman Empire or only the province of Judaea?
Now in those days a decree went out from Caesar Augustus, that a census be taken of all the inhabited earth. - Luke 2:1 (NASB)
One of them, named Agabus, stood up and indicated by the Spirit that there would definitely be a severe famine all over the world. And this took place in the reign of Claudius. - Acts 11:28 (NASB)
In these verses, the expressions "world" and "inhabited earth" are, in Koine Greek, οἰκουμένην.