Long Run Timber Supply: Price Elasticity, Inventory Elasticity, and the Capital-Output Ratio

Timber production requires substantially more capital per unit output than do most economic enterprises. The quantity of capital deployed depends primarily on the rotation length and the output price of stumpage. In a long run timber supply model this gives rise to a "backward bending" supply curve. This paper summarizes a long run model of timber supply, and computes the associated price and inventory elasticities. The role of capital in timber production is explored through a continuous time formulation of the usual Faustmann point input/point output model. The theoretical results are illustrated through an example based on loblolly pine yields

When is the Optimal Economic Rotation Longer than the Rotation of Maximum Sustained Yield?

Contrary to the assertions of many, the rotation which maximizes the net present value of timber receipts may be longer than the rotation which maximizes average annual physical yield. This circumstance may arise even in a very simple economic model once regeneration costs are recognized. Along with a theoretical comparison of the two rotation criteria, an example using Pinus patula plantations in Tanzania demonstrates the potential practical importance of this conclusion

The Global Forest Sector: An Analytical Perspective

The world's forests, like its oceans and atmosphere, are global resources. Tree-covered landscapes blanket large parts of every major land mass except Antarctica and contribute to the well being of every individual on earth. Properly managed, they provide a myriad of products -- from medicinal plants to cooking fuel to building materials to fine papers to special chemicals that serve as a base for plastics and other synthetic products. Reservoirs of enormous genetic diversity, forests comprise the habitats for a large share of the Earth's 10 million species of living things. Forests cleanse the air we breathe and the water we drink. It is not too much to say that the health of the forests underlies the health of mankind itself. Yet this global resource, and the multitude of products derived from it, have rarely been studied from a global perspective. In 1980, the International Institute for Applied Systems Analysis (IIASA) organized its Forest Sector Project (FSP) precisely to examine this global resource from a global perspective. This five-year project developed a computer-based model of the world's forest sector -- forest resources, conversion processes, and international trade in forest products -- and examined the global effects of national resource, industry, and trade policies. In addition to a small core team of scientists at IIASA, the FSP included a collaborative network of over 300 scientists, managers, and policymakers. Besides the model itself, one of the important products of that collaboration was a book entitled "The Global Forest Sector: An Analytical Perspective." This report is a synopsis of that book

The Global Forest Sector: An Analytical Perspective

This book is the final report of the Forest Sector Project at The International Institute for Applied Systems Analysis (IIASA). The primary goal of the Project was to study long-term developments in the production, consumption, and world trade of forests products. The aim was to aid in the formulations of investment strategy in forest industrial companies and of forestry and forest industrial policies in different world regions by governmental agencies and international authorities. For this purpose, a global model of the forest sector was built and, employing this model, a number of scenarios were developed. Based on conservative assumptions, the base scenario served as a reference for making judgements about the relative impacts of alternative assumptions. The scenario variations were chosen to study the impact of alternative rates of economic growth, changes in currency exchange rates, impact of trade liberalization, impact of environmental changes, etc. The scenarios should not be regarded as unbiased forecasts, but rather as conditional forecasts aiming to answer what-if questions. For the practitioner to fully use the Project results, it is necessary to develop additional scenarios that are particularly relevant to the policy issues concerned

Observation of Orbitally Excited B_s Mesons

We report the first observation of two narrow resonances consistent with states of orbitally excited (L=1) B_s mesons using 1 fb^{-1} of ppbar collisions at sqrt{s} = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron. We use two-body decays into K^- and B^+ mesons reconstructed as B^+ \to J/\psi K^+, J/\psi \to \mu^+ \mu^- or B^+ \to \bar{D}^0 \pi^+, \bar{D}^0 \to K^+ \pi^-. We deduce the masses of the two states to be m(B_{s1}) = 5829.4 +- 0.7 MeV/c^2 and m(B_{s2}^*) = 5839.7 +- 0.7 MeV/c^2.Comment: Version accepted and published by Phys. Rev. Let

Global Search for New Physics with 2.0/fb at CDF

Data collected in Run II of the Fermilab Tevatron are searched for indications of new electroweak-scale physics. Rather than focusing on particular new physics scenarios, CDF data are analyzed for discrepancies with the standard model prediction. A model-independent approach (Vista) considers gross features of the data, and is sensitive to new large cross-section physics. Further sensitivity to new physics is provided by two additional algorithms: a Bump Hunter searches invariant mass distributions for "bumps" that could indicate resonant production of new particles; and the Sleuth procedure scans for data excesses at large summed transverse momentum. This combined global search for new physics in 2.0/fb of ppbar collisions at sqrt(s)=1.96 TeV reveals no indication of physics beyond the standard model.Comment: 8 pages, 7 figures. Final version which appeared in Physical Review D Rapid Communication

Search for chargino-neutralino production in ppbar collisions at sqrt(s) = 1.96 TeV

We present the results of a search for associated production of the chargino and neutralino supersymmetric particles using up to 1.1 fb-1 of integrated luminosity collected by the CDF II experiment at the Tevatron ppbar collider at a center-of-mass energy of 1.96 TeV. The search is conducted by analyzing events with a large transverse momentum imbalance and either three charged leptons or two charged leptons of the same electric charge. The numbers of observed events are found to be consistent with standard model expectations. Upper limits on the production cross section are derived in different theoretical models. In one of these models a lower limit on the mass of the chargino is set at 129 GeV/c^2 at the 95% confidence level.Comment: To be submitted to Phys.Rev.Let

Measurement of the ttbar Production Cross Section in ppbar collisions at sqrt s = 1.96 TeV in the All Hadronic Decay Mode

We report a measurement of the ttbar production cross section using the CDF-II detector at the Fermilab Tevatron. The analysis is performed using 311 pb-1 of ppbar collisions at sqrt(s)=1.96 TeV. The data consist of events selected with six or more hadronic jets with additional kinematic requirements. At least one of these jets must be identified as a b-quark jet by the reconstruction of a secondary vertex. The cross section is measured to be sigma(tbart)=7.5+-2.1(stat.)+3.3-2.2(syst.)+0.5-0.4(lumi.) pb, which is consistent with the standard model prediction.Comment: By CDF collaboratio