Detailed operating instructions are described for SIMAC, a computerized forest simulation model which calculates the allowable cut assuming volume regulation for forests with intensively managed stands. A sample problem illustrates the required inputs and expected output. SIMAC is written in FORTRAN IV and runs on a CDC 6400 computer with a SCOPE 3.3 operating system. The conceptual basis of the SIMAC method is not discussed in detail.

The contributions for over 80 years by scientists at the Pacific Northwest Research Station to developments in economic theory, economic tools, policies, and economic issues are summarized. This is a story of progressive accomplishments set against a constantly changing background of economic and social events.

February issue includes Appendix entitled Directory of United States Government periodicals and subscription publications; September issue includes List of depository libraries; June and December issues include semiannual index.