 Recent generational accounting by the IMF and fiscal gap accounting by Kotlikoff claim to confirm the truly severe long-run fiscal problems facing the U.S.In the late 1970s, Kotlikoff, together with Berkeley economist, Alan J. Auerbach, developed the first large-scale computable general equilibrium life-cycle model that can track the behavior, over time, of economies comprising large numbers of overlapping generations.The model and its offspring have been used extensively to study future fiscal and demographic transitions in the U.S. and abroad.