The democratic method has been found to be the most effective leadership style? true or false?

Yes, it is true that the democratic method has been found to be the most effective leadership style, since this is the most inclusive, although this is not always the case. 

Contributing factors  leading  to the harlem renaissance were the great migration of african americans to northern cities, which concentratedambitious  people in places where they could encourage each  other, and the first world war, which had created new industrial work opportunities for tens of thousands of people.