Why has democracy consolidated in some countries but others have experienced democratic stalling or reversal?

Roughly 900 words.

This is a comparative analysis, please ensure the answer sticks well with the question

Thematic Readings:

Bunce, Valerie Comparative Democratization. Big and Bounded Generalizations, Comparative Political Studies 33, 6/7 (2000): 703-734.

Carothers, Thomas The End of the Transition Paradigm, in Journal of Democracy 13, 1 (January 2002), 5-21.

Ross, Michael Lewin Does Oil Hinder Democracy? World Politics 53, 3 (April 2001): 325-61

David Collier, Steve Levistky, Democracy with adjectives: conceptual innovation in comparative research, World Politics 49 (3), April 1997, p.430-51

Diamond, Larry. Leonardo Morlino, The quality of democracy: an overview, Journal of Democracy, 15(4), October 2004, p20-31.

Grugel, Jean, Democratization: A Critical Introduction (London: Palgrave Macmillan, 2009), 1-67 & 217-237.