Were economic factors the driving force behind imperial expansion during the Age of 'New Imperialism' c1870-1914?

Historians such as J Hobson, and Marxist writers eg Lenin, have all argued that economic factors were the driving force behind imperial expansion. The effects of the industrial revolution and the consequent oversupply of goods for domestic markets, according to the aforementioned historians, necessitated colonial acquisition as a means of obtaining access to foreign markets. This argument is known as the underconsumption theory and was developed by Hobson.Having said this, colonisation was not a simple process and involved many motivations. One significant factor was that of humanitarianism (in the eyes of the coloniser). Europeans believed that they had a duty to 'civilise' the Orient. This was dubbed the mission civilisatrice and originated in France- Jules Ferry was very prominent. Civilising involved bringing the benefits of Western institutions and practice to the colonies. eg Christianity, democracy etc