I know that the proximity to the Atlantic Sea played a role in this for the NW countries due to the New World (Age of Exploration and such), but the rest of the factors seem widely debated.
This question needs some elaboration of assumptions because I think it is problematic conceptualization:
Where do you think the economic center of gravity was prior to 1450? IE where did it shift from? What are the key economic indicators of this 'shift' for you?
What countries/regions do you include in NW Europe during this time?