Economics of Douglas fir management revisited

TL;DR

This paper revisits Douglas fir management economics, revealing shorter rotation times and the impact of evolving prices and expenses on profit rates, while showing that optimal rotations are unaffected by price and expense evolution.

Contribution

It introduces a revised economic model for Douglas fir management that accounts for evolving prices and expenses, altering previous rotation time estimates.

Findings

Shorter rotation times than earlier studies.

Evolving prices and expenses affect profit rates and rotation lengths.

Optimal rotations are independent of price and expense evolution.

Abstract

A recent Douglas fir management investigation is repeated in terms of accounting measures. The rotation times become much shorter than in earlier results. Thinnings do not become feasible, provided the thinning effects on the volumetric yield function do not evolve in time. Evolving prices and expenses break the periodic boundary condition in monetary quantities: profit rates and capitalizations evolve with prices. The periodic boundary condition is, however, retained in time derivatives of dimensionless quantities, as well as in physical characteristics of rotations optimized for the rate of return. Then, optimal rotations do not depend on the evolution of prices and expenses. Relatively high timber prices shorten rotations, as relatively high expenses extend them.