BIOFUELS, CLIMATE POLICY, AND WATER MANAGEMENT: ASSESSING POLICY-INDUCED SHIFTS ON AGRICULTURE’S EXTENSIVE AND INTENSIVE MARGINS

Biofuel expansion efforts and climate mitigation policy could fundamentally alter land management trends in U.S. agriculture and forestry (AF) by mandating biofuel feedstock production and providing incentives for greenhouse gas (GHG) emissions reduction and carbon sequestration from terrestrial sources. Research has shown that biofuel expansion can alter commodity markets, induce agricultural land expansion, and intensify production. Meanwhile, GHG mitigation efforts could limit agricultural expansion, reduce current cultivation, and lower management intensity by incentivizing GHG emissions reduction and carbon sequestration within AF. To date, little work has attempted to quantify biofuel and climate policy-induced shifts together along the extensive and intensive agricultural production margins within a systems-based framework, though such shifts could have resounding implications on agricultural water consumption and quality. This study uses a comprehensive and detailed economic model of the U.S. AF sectors to simulate land management responses to biofuel expansion and GHG policies. While bioenergy production and altered AF management practices are found to significantly reduce GHG emissions, additional water consumption and nutrient use are possible policy outcomes. Specifically, we find that policies that influence shifts to the extensive margin will increase aggregate water use and nutrient application, but lead to lower intensity per-unit area. Conversely, when combined with biofuel mandates climate mitigation incentives lower agricultural land expansion, but lead to higher levels of management intensity. Somewhat contrary to expectations, GHG mitigation incentives cause water and nutrient use intensity to grow at an increasing rate due to the greater level of land use competition. Additionally, important regional trends emerge, as water use and quality concerns grow with the CO2 price in areas with limited GHG mitigation possibilities. This suggests that “water leakage” is possible whereby emissions reduction activities decrease output in one region and stimulate management intensity elsewhere. The potential indirect consequences of combined biofuel and climate mitigation incentives on water resource systems warrant further attention in policy design and future research.Greenhouse gas mitigation, biofuels, water resource management, Environmental Economics and Policy, Production Economics, Resource /Energy Economics and Policy,

Five Principles for Vertical Merger Enforcement Policy

There seems to be consensus that the Department of Justice’s 1984 Vertical Merger Guidelines do not reflect either modern theoretical and empirical economic analysis or current agency enforcement policy. Yet widely divergent views of preferred enforcement policies have been expressed among agency enforcers and commentators. Based on our review of the relevant economic literature and our experience analyzing vertical mergers, we recommend that the enforcement agencies adopt five principles: (i) The agencies should consider and investigate the full range of potential anticompetitive harms when evaluating vertical mergers; (ii) The agencies should decline to presume that vertical mergers benefit competition on balance in the oligopoly markets that typically prompt agency review, nor set a higher evidentiary standard based on such a presumption; (iii) The agencies should evaluate claimed efficiencies resulting from vertical mergers as carefully and critically as they evaluate claimed efficiencies resulting from horizontal mergers, and require the merging parties to show that the efficiencies are verifiable, merger-specific and sufficient to reverse the potential anticompetitive effects; (iv) The agencies should decline to adopt a safe harbor for vertical mergers, even if rebuttable, except perhaps when both firms compete in unconcentrated markets; (v) The agencies should consider adopting rebuttable anticompetitive presumptions that a vertical merger harms competition when certain factual predicates are satisfied. We do not intend these presumptions to describe all the ways by which vertical mergers can harm competition, so the agencies should continue to investigate vertical mergers that raise concerns about input and customer foreclosure, loss of a disruptive or maverick firm, evasion of rate regulation or other threats to competition, even if the specific factual predicates of the presumptions are not satisfied

Circumpolar Diversity and Geographic Differentiation of mtDNA in the Critically Endangered Antarctic Blue Whale (Balaenoptera musculus intermedia)

To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work.\ud This is the publisher’s final pdf. The published article is copyrighted by the Public Library of Science and can be found at: http://www.plosone.org/home.action.The Antarctic blue whale (Balaenoptera musculus intermedia) was hunted to near extinction between 1904 and 1972, declining from an estimated initial abundance of more than 250,000 to fewer than 400. Here, we describe mtDNA control region diversity and geographic differentiation in the surviving population of the Antarctic blue whale, using 218 biopsy samples collected under the auspices of the International Whaling Commission (IWC) during research cruises from 1990-2009. Microsatellite genotypes and mtDNA sequences identified 166 individuals among the 218 samples and documented movement of a small number of individuals, including a female that traveled at least 6,650 km or 131 degrees longitude over four years. mtDNA sequences from the 166 individuals were aligned with published sequences from 17 additional individuals, resolving 52 unique haplotypes from a consensus length of 410 bp. From this minimum census, a rarefaction analysis predicted that only 72 haplotypes (95% CL, 64, 86) have survived in the contemporary population of Antarctic blue whales. However, haplotype diversity was relatively high (0.968 +/- 0.004), perhaps as a result of the longevity of blue whales and the relatively recent timing of the bottleneck. Despite the potential for circumpolar dispersal, we found significant differentiation in mtDNA diversity (F-ST = 0.032, p<0.005) and microsatellite alleles (F-ST = 0.005, p<0.05) among the six Antarctic Areas historically used by the IWC for management of blue whales

BIOFUELS, CLIMATE POLICY, AND WATER MANAGEMENT: ASSESSING POLICY-INDUCED SHIFTS ON AGRICULTURE’S EXTENSIVE AND INTENSIVE MARGINS

Biofuel expansion efforts and climate mitigation policy could fundamentally alter land management trends in U.S. agriculture and forestry (AF) by mandating biofuel feedstock production and providing incentives for greenhouse gas (GHG) emissions reduction and carbon sequestration from terrestrial sources. Research has shown that biofuel expansion can alter commodity markets, induce agricultural land expansion, and intensify production. Meanwhile, GHG mitigation efforts could limit agricultural expansion, reduce current cultivation, and lower management intensity by incentivizing GHG emissions reduction and carbon sequestration within AF. To date, little work has attempted to quantify biofuel and climate policy-induced shifts together along the extensive and intensive agricultural production margins within a systems-based framework, though such shifts could have resounding implications on agricultural water consumption and quality. This study uses a comprehensive and detailed economic model of the U.S. AF sectors to simulate land management responses to biofuel expansion and GHG policies. While bioenergy production and altered AF management practices are found to significantly reduce GHG emissions, additional water consumption and nutrient use are possible policy outcomes. Specifically, we find that policies that influence shifts to the extensive margin will increase aggregate water use and nutrient application, but lead to lower intensity per-unit area. Conversely, when combined with biofuel mandates climate mitigation incentives lower agricultural land expansion, but lead to higher levels of management intensity. Somewhat contrary to expectations, GHG mitigation incentives cause water and nutrient use intensity to grow at an increasing rate due to the greater level of land use competition. Additionally, important regional trends emerge, as water use and quality concerns grow with the CO2 price in areas with limited GHG mitigation possibilities. This suggests that “water leakage” is possible whereby emissions reduction activities decrease output in one region and stimulate management intensity elsewhere. The potential indirect consequences of combined biofuel and climate mitigation incentives on water resource systems warrant further attention in policy design and future research

Limitations for change detection in multiple Gabor targets

We investigate the limitations on the ability to detect when a target has changed, using Gabor targets as simple quantifiable stimuli. Using a partial report technique to equalise response variables, we show that the log of the Weber fraction for detecting a spatial frequency change is proportional to the log of the number of targets, with a set-size effect that is greater than that reported for visual search. This is not a simple perceptual limitation, because pre-cueing a single target out of four restores performance to the level found when only one target is present. It is argued that the primary limitation on performance is the division of attention across multiple targets, rather than decay within visual memory. However in a simplified change detection experiment without cueing, where only one target of the set changed, not only was the set size effect still larger, but it was greater at 2000 msec ISI than at 250 msec ISI, indicating a possible memory component. The steepness of the set size effects obtained suggests that even moderate complexity of a stimulus in terms of number of component objects can overload attentional processes, suggesting a possible low-level mechanism for change blindness

Improved Quantum Hard-Sphere Ground-State Equations of State

The London ground-state energy formula as a function of number density for a system of identical boson hard spheres, corrected for the reduced mass of a pair of particles in a sphere-of-influence picture, and generalized to fermion hard-sphere systems with two and four intrinsic degrees of freedom, has a double-pole at the ultimate \textit{regular} (or periodic, e.g., face-centered-cubic) close-packing density usually associated with a crystalline branch. Improved fluid branches are contructed based upon exact, field-theoretic perturbation-theory low-density expansions for many-boson and many-fermion systems, appropriately extrapolated to intermediate densities, but whose ultimate density is irregular or \textit{random} closest close-packing as suggested in studies of a classical system of hard spheres. Results show substantially improved agreement with the best available Green-function Monte Carlo and diffusion Monte Carlo simulations for bosons, as well as with ladder, variational Fermi hypernetted chain, and so-called L-expansion data for two-component fermions.Comment: 15 pages and 7 figure

Recommendations and Comments on the Draft Vertical Merger Guidelines

These recommendations and comments respond to the request by the Federal Trade Commission and the Department of Justice’s Antitrust Division for public comment on the draft 2020 Vertical Merger Guidelines. We commend the agencies for updating the 1984 non-horizontal merger guidelines by recognizing the substantial advances in economic thinking about vertical mergers in the thirty-five years since those guidelines were issued. Our comments emphasize four issues: (i) the treatment of the elimination of double marginalization (“EDM”), particularly that the draft vertical merger guidelines appear inappropriately to make proof of cognizability part of the agencies burden and that they appear to inappropriately treat the merging firm’s failure to have eliminated double marginalization pre-merger as proof that the merger would lead to EDM and that the post-merger EDM would be merger-specific; (ii) the seemingly arbitrary and inappropriately permissive safe harbor; (iii) the inappropriate (though perhaps unintended) apparent requirement that harms be quantified; and (iv) the inappropriate (though perhaps unintended) apparent requirement that the agencies show that foreclosure would not have been profitable before the merger. We are concerned that these features of the draft Guidelines will lead to under-enforcement and false negatives (including under-deterrence)

Carbon source/sink information provided by column CO2 measurements from the Orbiting Carbon Observatory

© The Authors, 2010. This article is distributed under the terms of the Creative Commons Attribution 3.0 License. The definitive version was published in Atmospheric Chemistry and Physics 10 (2010): 4145-4165, doi:10.5194/acp-10-4145-2010.We quantify how well column-integrated CO2 measurements from the Orbiting Carbon Observatory (OCO) should be able to constrain surface CO2 fluxes, given the presence of various error sources. We use variational data assimilation to optimize weekly fluxes at a 2°×5° resolution (lat/lon) using simulated data averaged across each model grid box overflight (typically every ~33 s). Grid-scale simulations of this sort have been carried out before for OCO using simplified assumptions for the measurement error. Here, we more accurately describe the OCO measurements in two ways. First, we use new estimates of the single-sounding retrieval uncertainty and averaging kernel, both computed as a function of surface type, solar zenith angle, aerosol optical depth, and pointing mode (nadir vs. glint). Second, we collapse the information content of all valid retrievals from each grid box crossing into an equivalent multi-sounding measurement uncertainty, factoring in both time/space error correlations and data rejection due to clouds and thick aerosols. Finally, we examine the impact of three types of systematic errors: measurement biases due to aerosols, transport errors, and mistuning errors caused by assuming incorrect statistics. When only random measurement errors are considered, both nadir- and glint-mode data give error reductions over the land of ~45% for the weekly fluxes, and ~65% for seasonal fluxes. Systematic errors reduce both the magnitude and spatial extent of these improvements by about a factor of two, however. Improvements nearly as large are achieved over the ocean using glint-mode data, but are degraded even more by the systematic errors. Our ability to identify and remove systematic errors in both the column retrievals and atmospheric assimilations will thus be critical for maximizing the usefulness of the OCO data.SD and DB acknowledge support from NASA grant NNG06G127G. DB also acknowledges initial support from NOAA Grant NA16GP2935

Overwinter survival and post-release movements of translocated water voles: implications for current mitigation guidance

Translocation is currently used as a last resort mitigation strategy for water voles (Arvicola amphibius) in the UK (Dean et al. 2016), where populations have undergone widespread declines during the past century. To increase the chances of success, current guidance suggests translocation of voles during autumn should not be carried out as individuals may be at higher risk of overwinter mortality, and instead should be overwintered in captivity for release the following spring. To verify this guidance, we carried out a mark recapture and radiotracking study of an autumn translocated and resident population in lowland England. Whilst we found translocated voles undertook longer exploratory movements than residents and those previously recorded in spring, there was no evidence from our study that translocated voles suffered higher mortality rates compared to the resident individuals. The turnover in both populations was high with 25% and 8% of the translocated and resident individuals being recaptured in spring. Younger voles that were not collared had a significantly higher chance of being recaptured in spring and their survival and settlement on the receptor channel is considered important as this is the age class that will produce most of the following years’ young. Mean weekly distances moved by collared voles showed no pattern of stabilisation, in either sex, over the 10-week monitoring period and combined dispersal from both study populations accounted for 26% of those that were not recaptured in spring. However, due to low sample size, we were unable to distinguish between the effects of dispersal and mortality. We conclude that where individuals or populations will be negatively impacted by planned development, autumn translocations in lowland England may offer a feasible alternative to housing animals in captivity, given the high financial cost and additional health and welfare risks associated with a captive environment. The receptor site and adjacent habitat (> 1 km) would need to support a seasonal abundance of food and cover, be connected to existing populations and be part of a wider landscape that is mink free and under an effective mink control programme to help secure long-term population viability. We advise, however, that due to our small sample size, further studies are undertaken to confirm our findings

A Uniform Analysis of the Ly-alpha forest at z = 0 - 5: I. The sample and distribution of clouds at z > 1.7

We present moderate resolution data for 39 QSOs at z $\approx$ 2 obtained at the Multiple Mirror Telescope. These data are combined with spectra of comparable resolution of 60 QSOs with redshifts greater than 1.7 found in the literature to investigate the distribution of Ly-alpha forest lines in redshift and equivalent width. We find a value for $\gamma$, the parameter describing the number distribution of Ly-alpha forest lines in redshift, of $1.88\pm0.22$ for lines stronger than a rest equivalent width of 0.32 $\AA$, in good agreement with some previous studies. The Kolmogorov-Smirnov test was applied to the data and it is found that this single power law is a good fit over the relevant redshift ranges. Simulations of the Lyman alpha forest were performed to determine the completeness of the line lists and to test how well the analysis the underlying line statistics, given this level of completeness.Comment: minor corrections to text, 37 Latex pages, 11 encapsulated Postscript figures, uses emulateapj.sty, To appear in the Sept. 2000 ApJS, line lists and spectra available at http://qso.as.arizona.edu/~jscott/Spectra/index.htm