The past two decades have seen a substantial increase in the use of computational methods to solve dynamic general equilibrium problems. These methods are being used to analyze problems in, for example, public finance, dynamic models of asset markets, agricultural economics, and macroeconomics. The early computational methods relied primarily on intuitive economic tatonnement stories. While these methods often worked, they are often slow. Also, we know from general equilibrium theory that tatonnement methods may not converge. In the past decade the computational literature has made more use of formal mathematical tools, particularly from numerical analysis. This has resulted in more powerful algorithms which can attack increasingly complex problems, a necessity when it comes to solving models with several agents. It is particularly appropriate that there be a survey of this literature for the 2000 World Congress of the Econometric Society. Ragnar Frisch, in his editorial in the initial issue of Econometrica, defined econometrics as the" unification of the theoretical-quantitative and the empirical-quantitative approach to economic problems." He said:

This emphasis on the quantitative aspect of economic problems has a profound significance. Economic life is a complex network of relationships operating in all directions. Therefore, so long as we confine ourselves to statements in general terms about one economic factor having an effect on some other factor, almost any sort of relationship may be selected, postulated as a law, and explained by a plausible argument. Thus, there exist a real danger of advancing statements and conclusions which-although true as tendencies in a very restricted sense-are nevertheless thoroughly inadequate, or even misleading if offered as an explanation of the situation. To use an extreme illustration, they may be just as deceptive as to say that when a man tries to row a boat forward, the boat will be driven backward because of the pressure exerted by his feet. The rowboat situation is not, of course, explained by finding out that there exists a pressure in one direction or another, but only by comparing the relative magnitudes of a number of pressures and counter-pressures. It is this comparison of magnitudes that gives a real significance to the analysis. Many, if not most, of the situations we have to face in economics are of just this sort.