Valerie Percival and Thomas Homer-Dixon | On April 6, 1994, President Juvenal Habyarimana’s plane exploded in the skies above the Kigali region of Rwanda. Violence gripped the country. Between April and August of 1994, as many as 1 million people were killed and more than 2 million people became refugees.
This paper shows that some commonly advocated methodological principles of modern political science are inappropriate for the study of complex ecological-political systems. It also provides conceptual tools for thinking about the causal roles of environmental and demographic factors, and it discusses various strategies for hypothesis and inference testing.