The modern mathematical economics literature is permeated with dynamics. This starts with a simple tatonnement story of how prices adjust according to supply and demand, and it continues with the more sophisticated price adjustment models which involve speculation, etc. Dynamics arise from the Euler, or the Bellman equations, to define the optimal paths in growth models, as well as in other optimization problems. Arguments based upon dynamics are advanced to justify various forms of equilibria; here we find issues such as the accessibility of pareto points or the comparison of different bargaining solution concepts. In recent years, as manifested by several of the papers presented at this conference, dynamics has been used to explain non-stationary behavior such as business cycles.