Effects of econometric and activity analysis derived supply curves on Canadian sawmilling industry market forecasts

This study utilizes the Timber Assessment Market Model (TAMM) to examine the differences in Canadian softwood lumber market forecasts arising from econometric versus activity analysis supply curves. A restricted profit function approach is applied to three lumber producing regions using the most recent data available on costs, prices, and output to estimate the econometric supply curve along with factor demands. The corresponding own- and cross-price elasticities along with the elasticities of substitution are estimated and compared to past studies. An activity analysis supply curve is presented utilizing two production technologies. Market forecasts for the period 1996- 2005 are estimated via the TAMM model. A comparison of TAMM solutions for a base case and three exogenous shock scenarios is presented. Similar price and quantity values are obtained in the historic period, while the activity analysis provide a much more volatile reaction to exogenous stimuli

Evaluating land-use and private forest management responses to a potential forest carbon offset sales program in western Oregon (USA)

We describe the use of linked land-use and forest sector models to simulate the effects of carbon offset sales on private forest owners' land-use and forest management decisions in western Oregon (USA). Our work focuses on forest management decisions rather than afforestation, allows full forest sector price adjustment to land-use changes, and incorporates time-dependent costs and restrictions of offset programs. The land-use model utilizes structure count data on some 21,000 plots spanning 30 years. The intertemporal optimizing forest sector model employs mill-level demand and FIA plot-level inventory. Our linked simulation modeling projects that an offset sales program could reduce forest land loss to development in western Oregon by about 4700 acres over the 2010-2060 simulation period for each $1 increase in the carbon price. At$10 per tonne CO₂, regional private carbon stocks would be roughly stabilized at current levels over the period to 2060. Rotations would lengthen on enrolled lands, as expected, but use of planting, thinning and uneven-aged management would decline.Keywords: Climate change, Silviculture, Carbon markets, Carbon storage, Forest land developmen

Private timber harvest potential in Eastern Oregon

Growing stock inventory on industrial and nonindustrial private forest (NIPF) lands in eastern Oregon has declined over the past 20 yr, as harvesting and mortality losses to insects and disease have outpaced growth. Over the same time period, harvest rates on private lands have varied, with no distinct trend to the variation. In the most recent survey (1999), industrial and NIPF inventories differed by less than 8% (1.786 billion ft³ versus 1.655 billion ft³), while the NIPF timberland base was only two-thirds of the industrial base (1.105 million ac versus 1.603 million ac). This study employs recent inventories and even-flow and market-based harvest simulators to develop projections of future harvest potentials. For industrial lands, even-flow and market-based projections of future harvest potential over the next 50 yr are approximately half of average harvests over the past 40 yr. For NIPF lands the even-flow projection is 20% higher than the historical harvest average, while the market-based projection indicates potential for a substantial but short-lived increase in near-term harvest. Inventories on industrial lands rise under both projections, while NIPF inventories remain fairly stable. Continued loss of land from NIPF ownerships to other owners and uses has limited influence on the market-based NIPF harvest projection until after 2050. A simulated policy of expanded riparian protection zones reduces harvest on both ownerships roughly in proportion to the area removed from the harvestable land base. A simulated requirement to retain 30% more residual volume in partially cut stands reduces harvest by 5% on combined private ownerships and increases total inventory by 13% after 50 yr

Timber harvest projections for private land in western Oregon

In this analysis, volume-flow and market-based models of the western Oregon timber sector are developed. The volume-flow model finds the maximum, long-term, even-flow level of cut for each ownership (industry and non-industrial private forest). The market model simulates the interaction of log demand and timber owner supply to find the market balancing harvest quantity and log price. In both models, owner decisions on the intensity of timber management (silviculture) are made within the models consistent with owner objectives (volume or wealth maximization). Model projections suggest that western Oregon forest industry owners could sustain cut at recent (1995–1999) levels, stemming the 40-yr declining trend in their harvest. Nonindustrial private forest owners could raise harvests to near historical peak levels. These harvests could be maintained over the next five decades with no reduction in the growing stock inventory. Management would continue to shift toward the more intensive forms on both ownerships. The average age of the inventory would decline over the projection. Simulated riparian protection policies lower harvest roughly in proportion to the land base reduction and raise log prices. A policy to increase the minimum age of clearcut harvests would lead to large near-term reductions in industrial harvest but less marked reductions on NIPF lands. Prices would rise sharply in the near term. Over the longer term, the policy would act to expand inventory, raising harvest, and to depress prices

Mycophenolate mofetil versus cyclosporine for remission maintenance in nephrotic syndrome

We performed a multi-centre randomized controlled trial to compare the efficacy of mycophenolate mofetil (MMF) to that of cyclosporine A (CsA) in treating children with frequently relapsing nephrotic syndrome and biopsy-proven minimal change disease. Of the 31 randomized initially selected patients, seven were excluded. The remaining 24 children received either MMF 1200 mg/m2per day (n = 12) or CsA 4-5 mg/kg per day (n = 12) during a 12-month period. Of the 12 patients in the MMF group, two discontinued the study medication. Evaluation of the changes from the baseline glomerular filtration rate showed an overall significant difference in favour of MMF over the treatment period (p = 0.03). Seven of the 12 patients in the MMF group and 11 of the 12 patients in the CsA group remained in complete remission during the entire study period. Relapse rate in the MMF group was 0.83/year compared to 0.08/year in the CsA group (p = 0.08). None of the patients reported diarrhea. Pharmacokinetic profiles of mycophenolic acid were performed in seven patients. The patient with the lowest area under the curve had three relapses within 6 months. In children with frequently relapsing minimal change nephrotic syndrome, MMF has a favourable side effect profile compared to CsA; however, there is a tendency towards a higher relapse risk in patients treated with MMF

A Novel Mass Hierarchy and Discrete Excitation Spectra from Quantum-Fluctuating D-branes

We elaborate further on a recently proposed scenario for generating a mass hierarchy through quantum fluctuations of a single D3 brane, which represents our world embedded in a bulk five-dimensional space time. In this scenario, the quantum fluctuations of the D3-brane world in the bulk direction, quantified to leading order via a `recoil' world-sheet logarithmic conformal field theory approach, result in the dynamical appearance of a supersymmetry breaking (obstruction) scale alpha. This may be naturally taken to be at the TeV range, in order to provide a solution to the conventional gauge-hierarchy problem. The bulk spatial direction is characterized by the dynamical appearance of an horizon located at +- 1/alpha, inside which the positive energy conditions for the existence of stable matter are satisfied. To ensure the correct value of the four-dimensional Planck mass, the bulk string scale M_s is naturally found to lie at an intermediate energy scale of 10^{14} GeV. As an exclusive feature of the D3-brane quantum fluctuations (`recoil') we find that, for any given M_5, there is a discrete mass spectrum for four-dimensional Kaluza-Klein (KK) modes of bulk graviton and/or scalar fields. KK modes with masses 0 <= m < sqrt{2}alpha << M_s are found to have wavefunctions peaked, and hence localized, on the D3 brane at z=0.Comment: 21 pages latex, three eps figures incorporate

An econometric analysis of output supply and input demand in the Canadian softwood lumber industry

Few studies have examined the own-price elasticity of Canadian softwood lumber supply or output-adjusted factor demand elasticities over the past two decades, despite the utility of these measures in understanding producer response to tariffs, to market shifts (such as the decline in U.S. public harvest), and to changes in domestic forest policies. The present analysis employs a normalized, restricted quadratic profit function approach to estimate lumber supply and Marshallian factor demand elasticities for three Canadian regions. Results indicate that the lumber supply elasticity in the British Columbia coast region may be twice as large as that in the interior or eastern regions. Comparison of Hicksian factor demand elasticities with earlier studies suggests that the own price elasticity of labor demand may be two or more times larger than that for wood. Results also indicate differential time trends in Marshallian lumber output and wood demand elasticities across regions, rising in the British Columbia coast and falling elsewhere over the past two decades. Morishima elasticities of substitution from the present and past studies indicate that the wood for labor factor intensity is more sensitive to changes in labor price than is the labor for wood intensity to changes in wood price