Ritical review of Collier and Fearons articles

Essays to be used:
Ethnicity, Insurgency, and Civil War
Authors: James D. Fearon and David D. Laitin
Greed and grievance in civil war.
Authors: Paul Collier and Anke Hoeffler

Critical review of the operational definitions and measurements of key theoretical concepts developed in the two articles cited above. Please discuss (amongst other issues) the validity and reliability of the measurement.