This paper forms part of my doctoral dissertation at the University of Oslo.This paper surveys some recent work in the theoretical and econometric disequilibrium literature. The first .part of the paper gives an overview of some the main concepts used in the theory of non-Walrasian economics. These concepts give the theoretical background for a discussion of recent developments in the econometric disequilibrium literature. Particular emphasis is given to two recent developments. One is the virtual price approach of Lee (1986) and the other is the stochastic aggregation (smoothing by aggregation) approach used in Lambert (1988).This research was supported by the Norwegian Research Council for Science and the Humanitie