Susan Chodakewitz joined Nathan Associates, a premier economics consulting firm, as the new CEO.  She succeeded Lakhbir Singh, who retired after almost 39 years with Nathan. Susan previously worked at Tetra Tech where she served as president of its aviation management and information technology subsidiary, Tetra Tech AMT.  She also worked for SAIC, the Center for Strategic and International Studies, the Library of Congress and Booz, Allen & Hamilton.