The explosion in computer capacity in the past decade has been accompanied by a reorientation of econometrics toward using computer-intensive methods to reveal more about data and sharpen the inferences drawn. Innovations have been particularly intense in the areas of semiparametric and nonparametric estimation, use of resampling methods and cross-validation in parametric and nonparametric models, simulation methods for inference, estimation of dynamic stochastic programming models, and Bayesian methods. Translation of these methods into applications software and empirical econometrics has been uneven, partly because computational capacity has not been generally available. The primary objective of this project is to accelerate research on computationally intensive methods and applications, and to encourage more rapid testing , documentation, and dissemination of algorithms. It plans to provide UNIX workstations for a consortium of researchers working on computationally intensive econometrics, and a common file server to facilitate access to software and data. In addition to the facilities at Berkeley, described in this core proposal, there are subproposals from scholars at several other institutions who are working in the same area. The Berkeley file server will provide access not only for these scholars, but also for others not included in this proposal, to specialized software and data sets. The technology which is planned for both the Berkeley research programs and the consortium computing facility is well suited to the computing demands. It offers the promise of significant advances in theoretical econometric modelling methods.