The theory of lead markets has been criticized for not being "consistent and stringent".[9] While conventional wisdom, due to its emphasis on customer affluence and sophistication as inducers of innovation, has tended to see lead markets exist in economically highly developed countries; recent research, notably by Rajnish Tiwari and Cornelius Herstatt of Hamburg University of Technology (e.g. Tiwari and Herstatt, 2011a, Tiwari and Herstatt, 2011b), has emphasized the need to update/extend the lead market model to adjust it to the changing ground realities in the face of globalization and sustained economic growth in developing nations.