Efficiency Costs of Meeting Industry-Distributional Constraints under Environmental Permits and Taxes

Many pollution-related industries wield strong political influence and can e.ectively veto policy initiatives that would harm their profits.A politically realistic approach to environmental policy therefore seems to require the alleviation of significant profitlosses to these industries.The regulatory authority can do this by freely allocating some emissions permits or by exempting some inframarginal emissions from a pollution tax.However, such policies compel the government to forego an e.cient potential revenue source and to rely more heavily on ordinary distortionary taxes.As a result, achieving distributional objectives comes at a cost in terms of e.ciency.Using analytically and numerically solved equilibrium models, we analyze the e.- ciency costs implied by the distributional constraint that adverse impacts on profits in particular industries must be avoided.Both models indicate that the e.ciency cost implied by this constraint dwarfs the other e.ciency costs when the required amount of abatement is very small.When the abatement requirement becomes more extensive, however, the cost of this constraint diminishes relative to the other e.ciency costs of pollution-control.We also calculate the compensation ratio: the share of potential policy revenue that the government must forego to protect the industries in question.We show how this ratio is a.ected by the extent of abatement, supply and demand elasticities, and the potential for end-of-pipe treatment.One definition of this ratio corresponds to the share of pollution permits that must be freely allocated to prevent profit-losses in the targeted industries.Numerical simulations of sulfur dioxide pollution-control suggest that the Bush Administration s Clear Skies Initiative would exceed this ratio, freely allocating more permits than necessary to preserve profits.Our models also highlight significant di.erences between gross and net policy revenues: when abatement is extensive, a large fraction of the revenue collected from emissions permits or taxes is o.set by the revenue-loss from erosion of the base of existing factor taxes.efficiency;costs;environmental tax;pollution;environmental policy

Efficiency Costs of Meeting Industry-Distributional Constraints under Environmental Permits and Taxes

A politically realistic approach to environmental policy seems to require avoiding significant profit-losses in major pollution-related industries. The government can avoid such losses by freely allocating some emissions permits or by exempting some inframarginal emissions from a pollution tax. However, preventing profit-losses in this way involves an efficiency cost because it compels the government to forego especially efficient sources of revenue and to rely more heavily on ordinary, distortionary taxes. Using analytically and numerically solved equilibrium models, we analyze these efficiency costs. We find that when the required amount of abatement is small, the efficiency cost implied by the profits-constraint dwarfs the other efficiency costs of pollution-control. When the abatement requirement becomes more extensive, the cost of this constraint diminishes relative to the other efficiency costs. We also calculate and analyze the determinants of the gross compensation ratio' the share of pollution permits that must be freely allocated to prevent profit-losses in the targeted industries. Numerical simulations of sulfur dioxide pollution-control suggest that the Bush Administration's Clear Skies Initiative would exceed this ratio, freely allocating more permits than necessary to preserve profits.

Efficiency Costs of Meeting Industry-Distributional Constraints under Environmental Permits and Taxes

Many pollution-related industries wield strong political influence and can e.ectively veto policy initiatives that would harm their profits.A politically realistic approach to environmental policy therefore seems to require the alleviation of significant profitlosses to these industries.The regulatory authority can do this by freely allocating some emissions permits or by exempting some inframarginal emissions from a pollution tax.However, such policies compel the government to forego an e.cient potential revenue source and to rely more heavily on ordinary distortionary taxes.As a result, achieving distributional objectives comes at a cost in terms of e.ciency.Using analytically and numerically solved equilibrium models, we analyze the e.- ciency costs implied by the distributional constraint that adverse impacts on profits in particular industries must be avoided.Both models indicate that the e.ciency cost implied by this constraint dwarfs the other e.ciency costs when the required amount of abatement is very small.When the abatement requirement becomes more extensive, however, the cost of this constraint diminishes relative to the other e.ciency costs of pollution-control.We also calculate the compensation ratio: the share of potential policy revenue that the government must forego to protect the industries in question.We show how this ratio is a.ected by the extent of abatement, supply and demand elasticities, and the potential for end-of-pipe treatment.One definition of this ratio corresponds to the share of pollution permits that must be freely allocated to prevent profit-losses in the targeted industries.Numerical simulations of sulfur dioxide pollution-control suggest that the Bush Administration s Clear Skies Initiative would exceed this ratio, freely allocating more permits than necessary to preserve profits.Our models also highlight significant di.erences between gross and net policy revenues: when abatement is extensive, a large fraction of the revenue collected from emissions permits or taxes is o.set by the revenue-loss from erosion of the base of existing factor taxes

Characterization of host tolerance to Striga hermonthica

One of the most promising control options against the parasitic weed Striga hermonthica is the use of crop varieties that combine resistance with high levels of tolerance. The aim of this study was to clarify the relation between Striga infestation level, Striga infection level and relative yield loss of sorghum and to use this insight for exploring the options for a proper screening procedure for tolerance. In three pot experiments, conducted in Mali (2003) and The Netherlands (2003, 2004), four sorghum genotypes were exposed to a range of Striga infestation levels, ranging from 0.0625 to 16 seeds cm−3. Observations included regular Striga emergence counts and sorghum grain yield at maturity. There were significant genotype, infestation and genotype × infestation effects on sorghum yield. The relation between infestation level and infection level was density dependent. Furthermore, the relation between Striga infection level and relative yield loss was non-linear, though for the most resistant genotype Framida only the linear part of the relation was obtained, as even at high infestation levels only moderate infection levels were achieved. The results suggest that for resistant genotypes, tolerance can best be quantified as a reduced relative yield loss per aboveground Striga plant, whereas for less resistant genotypes the maximum relative yield loss can best be used. Whether both expressions of tolerance are interrelated could not be resolved. Complications of screening for tolerance under field conditions are discussed

WISP genes are members of the connective tissue growth factor family that are up-regulated in Wnt-1-transformed cells and aberrantly expressed in human colon tumors

Wnt family members are critical to many developmental processes, and components of the Wnt signaling pathway have been linked to tumorigenesis in familial and sporadic colon carcinomas. Here we report the identification of two genes, WISP-1 and WISP-2, that are up-regulated in the mouse mammary epithelial cell line C57MG transformed by Wnt-1, but not by Wnt-4. Together with a third related gene, WISP-3, these proteins define a subfamily of the connective tissue growth factor family. Two distinct systems demonstrated WISP induction to be associated with the expression of Wnt-1. These included (i) C57MG cells infected with a Wnt-1 retroviral vector or expressing Wnt-1 under the control of a tetracyline repressible promoter, and (ii) Wnt-1 transgenic mice. The WISP-1 gene was localized to human chromosome 8q24.1-8q24.3. WISP-1 genomic DNA was amplified in colon cancer cell lines and in human colon tumors and its RNA overexpressed (2- to >30-fold) in 84% of the tumors examined compared with patient-matched normal mucosa. WISP-3 mapped to chromosome 6q22-6q23 and also was overexpressed (4- to >40-fold) in 63% of the colon tumors analyzed. In contrast, WISP-2 mapped to human chromosome 20q12-20q13 and its DNA was amplified, but RNA expression was reduced (2- to >30-fold) in 79% of the tumors. These results suggest that the WISP genes may be downstream of Wnt-1 signaling and that aberrant levels of WISP expression in colon cancer may play a role in colon tumorigenesis

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Growth and photosynthetic responses of maize and sorghum to the parasitic weed Striga hermonthica

SIGLEAvailable from British Library Document Supply Centre-DSC:DXN023538 / BLDSC - British Library Document Supply CentreGBUnited Kingdo