Dear R users, The authors of the systemfit package have released a new version of this package with substantial enhancements. The systemfit package contains functions for fitting simultaneous systems of linear equations using Ordinary Least Squares (OLS), Weighted Least Squares (WLS), Seemingly Unrelated Regressions (SUR), Two-Stage Least Squares (2SLS), Weighted Two-Stage Least Squares (W2SLS), and Three-Stage Least Squares (3SLS). The new enhancements include the ability to test linear restrictions using an F, Wald or likelihood-ratio test and the ability to test model specification using the Hausman test. The major enhancements include better estimation using large data sets as well as many minor improvements, e.g. the ability to define how the residual covariance matrix and degrees of freedom are computed. The new version includes a wrapper function systemfitClassic that can be applied to (classical) panel-like data in long format. Furthermore, version 0.8-0 includes additional documentation (inst/doc/vignette_systemfit.pdf). Jeff D. Hamann Arne Henningsen
Jeff D. Hamann Forest Informatics, Inc. PO Box 1421 Corvallis, Oregon 97339-1421 phone 541-754-1428 jeff.hamann at forestinformatics.com www.forestinformatics.com and Arne Henningsen Department of Agricultural Economics University of Kiel Olshausenstr. 40 D-24098 Kiel (Germany) Tel: +49-431-880 4445 Fax: +49-431-880 1397 ahenningsen at agric-econ.uni-kiel.de http://www.uni-kiel.de/agrarpol/ahenningsen/