ADDIS ABABA UNIVERSITY SCHOOL OF GRADUATE STUDIES ESTIMATING HOUSEHOLD ENERGY DEMAND OF RURAL ETHIOPIA USING AN ALMOST IDEAL DEMAND SYSTEM (AIDS) BY DAWIT DIRIBA GUTA A thesis submitted to the School of Graduate Studies of Addis Ababa University in partial fulfillment of the requirement for Degree of Masters of Science in Economics (Natural Resource and Environmental Economics) June, 2008