11,054 research outputs found
Temporary Investment Tax Incentives: Theory with Evidence from Bonus Depreciation
Investment decisions are inherently forward-looking. The payoff of acquiring capital goods, particularly long-lived capital goods, is governed almost exclusively by events in the far future. Because the timing of the investment itself does not affect future payoffs, there are strong incentives to delay or accelerate investment to take advantage of predictable intertemporal variations in cost. For sufficiently long-lived capital goods, these incentives are so strong that the intertemporal elasticity of investment demand is nearly infinite. As a consequence, for a temporary tax change, the shadow price of long-lived capital goods must reflect the full tax subsidy regardless of the elasticity of investment supply. While price data provide no information on the elasticity of supply, they can reveal the extent to which adjustment costs are internal or external to the firm. In contrast, the elasticity of investment supply can be inferred from quantity data alone. The bonus depreciation allowance passed in 2002 and increased in 2003 presents an opportunity to test the sharp predictions of neoclassical investment theory. In the law, certain types of long-lived capital goods qualify for substantial tax subsides while others do not. The data show that investment in qualified properties was substantially higher than for unqualified property. The estimated elasticity of investment supply is high--between 10 and 20. Market prices do not react to the subsidy as the theory dictates. This suggests either that internal (unmeasured) adjustment costs play a significant role or that measurement problems in the price data effectively conceal the price changes. While the policy noticeably increased investment in types of capital that benefited substantially from bonus depreciation, the aggregate effects of the policy were modest. The analysis suggests that the policy may have increased output by roughly 0.1 percent to 0.2 percent and increased employment by roughly 100,000 to 200,000 jobs.
On the Optimization of Visualizations of Complex Phenomena
The problem of perceptually optimizing complex visualizations is a difficult one, involving perceptual as well as aesthetic issues. In our experience, controlled experiments are quite limited in their ability to uncover interrelationships among visualization parameters, and thus may not be the most useful way to develop rules-of-thumb or theory to guide the production of high-quality visualizations. In this paper, we propose a new experimental approach to optimizing visualization quality that integrates some of the strong points of controlled experiments with methods more suited to investigating complex highly-coupled phenomena. We use human-in-the-loop experiments to search through visualization parameter space, generating large databases of rated visualization solutions. This is followed by data mining to extract results such as exemplar visualizations, guidelines for producing visualizations, and hypotheses about strategies leading to strong visualizations. The approach can easily address both perceptual and aesthetic concerns, and can handle complex parameter interactions. We suggest a genetic algorithm as a valuable way of guiding the human-in-the-loop search through visualization parameter space. We describe our methods for using clustering, histogramming, principal component analysis, and neural networks for data mining. The experimental approach is illustrated with a study of the problem of optimal texturing for viewing layered surfaces so that both surfaces are maximally observable
Phased-In Tax Cuts and Economic Activity
Phased-in tax reductions are a common feature of tax legislation. This paper uses a dynamic general equilibrium model to quantify the effects of delaying tax cuts. According to the analysis of the model, the phased-in tax cuts of the 2001 tax law substantially reduced employment, output, and investment during the phase-in period. In contrast, the immediate tax cuts of the 2003 tax law provided significant incentives for immediate production and investment. The paper argues that the rules and accounting procedures used by Congress for formulating tax policy have a significant impact in shaping the details of tax policy and led to the phase-ins, sunsets, and temporary tax changes in both the 2001 and 2003 tax laws.Fiscal Policy, Tax Policy
Variations in the hospital management of self harm in adults in England: observational study
More than 140 000 people present to hospital after an
episode of self harm each year in England and Wales.
Improving the general hospital management of these
people is a key area in preventing suicide. Although
professional consensus has been reached on how self
harm services should be organised and delivered,
wide variations in care delivery have been reported in
two regions in England. Using a nationally
representative sample, we investigated the variation in
services and delivery of care for self harm patients in
hospitals in England
EVALUATING FACTORS INFLUENCING GROCERY STORE CHOICE
This paper analyzes consumer preferences toward grocery store choices given a set of attributes of stores. This information will then be used to make inferences on how the opening of a Wal-Mart supercenter would affect the other grocery stores in a small city.Consumer/Household Economics, Institutional and Behavioral Economics,
CAROLINA GOLDEN PRODUCTS
This case study focuses on an investment decision made in a poultry processing firm which is faced with increased sales targets but is constrained by dependence on other companies for storage and distribution. The decision to construct a distribution center is analyzed in this study. Instructors can use this case to teach agribusiness finance. As with other case studies, many issues can be explored, such as market channels, the importance of assumptions, and structure of the poultry industry.Agribusiness,
How to Evaluate your Question Answering System Every Day and Still Get Real Work Done
In this paper, we report on Qaviar, an experimental automated evaluation
system for question answering applications. The goal of our research was to
find an automatically calculated measure that correlates well with human
judges' assessment of answer correctness in the context of question answering
tasks. Qaviar judges the response by computing recall against the stemmed
content words in the human-generated answer key. It counts the answer correct
if it exceeds agiven recall threshold. We determined that the answer
correctness predicted by Qaviar agreed with the human 93% to 95% of the time.
41 question-answering systems were ranked by both Qaviar and human assessors,
and these rankings correlated with a Kendall's Tau measure of 0.920, compared
to a correlation of 0.956 between human assessors on the same data.Comment: 6 pages, 3 figures, to appear in Proceedings of the Second
International Conference on Language Resources and Evaluation (LREC 2000
The efficacy of problem-solving treatments after deliberate self-harm: meta-analysis of randomized controlled trials with respect to depression, hopelessness and improvement in problems
Background. Brief problem-solving therapy is regarded as a pragmatic treatment for deliberate self-harm (DSH) patients. A recent meta-analysis of randomized controlled trials (RCTs) evaluating this approach indicated a trend towards reduced repetition of DSH but the pooled odds ratio was not statistically significant. We have now examined other important outcomes using this procedure, namely depression, hopelessness and improvement in problems.
Method. Six trials in which problem-solving therapy was compared with control treatment were identified from an extensive literature review of RCTs of treatments for DSH patients. Data concerning depression, hopelessness and improvement in problems were extracted. Where relevant statistical data (e.g. standard deviations) were missing these were imputed using various statistical methods. Results were pooled using meta-analytical procedures.
Results. At follow-up, patients who were offered problem-solving therapy had significantly greater improvement in scores for depression (standardized mean difference =[minus sign]0·36; 95% CI [minus sign]0·61 to [minus sign]0·11) and hopelessness (weighted mean difference =[minus sign]3·2; 95% CI [minus sign]4·0 to [minus sign]2·41), and significantly more reported improvement in their problems (odds ratio = 2·31; 95% CI 1·29 to 4·13), than patients who were in the control treatment groups.
Conclusions. Problem-solving therapy for DSH patients appears to produce better results than control treatment with regard to improvement in depression, hopelessness and problems. It is desirable that this finding is confirmed in a large trial, which will also allow adequate testing of the impact of this treatment on repetition of DSH
Lipopolysaccharide and toll-like receptor 4 in dogs with congenital portosystemic shunts
Surgical attenuation of a congenital portosystemic shunt (CPSS) results in increased portal vein perfusion, liver growth and clinical improvement. Portal lipopolysaccharide (LPS) is implicated in liver regeneration via toll-like receptor (TLR) 4 mediated cytokine activation. The aim of this study was to investigate factors associated with LPS in dogs with CPSS. Plasma LPS concentrations were measured in the peripheral and portal blood using a limulus amoebocyte lysate (LAL) assay.
LPS concentration was significantly greater in the portal blood compared to peripheral blood in dogs with CPSS (P = 0.046) and control dogs (P = 0.002). LPS concentrations in the peripheral (P = 0.012) and portal (P = 0.005) blood of dogs with CPSS were significantly greater than those of control dogs. The relative mRNA expression of cytokines and TLRs was measured in liver biopsies from dogs with CPSS using quantitative PCR. TLR4 expression significantly increased following partial CPSS attenuation (P = 0.020). TLR4 expression was significantly greater in dogs that tolerated complete CPSS attenuation (P = 0.011) and those with good portal blood flow on pre-attenuation (P = 0.004) and post-attenuation (P = 0.015) portovenography. Serum interleukin (IL)-6 concentration was measured using a canine specific ELISA and significantly increased 24 h following CPSS attenuation (P < 0.001). Portal LPS was increased in dogs with CPSS, consistent with decreased hepatic clearance. TLR4 mRNA expression was significantly associated with portal blood flow and increased following surgery. These findings support the concept that portal LPS delivery is important in the hepatic response to surgical attenuation. Serum IL-6 significantly increased following surgery, consistent with LPS stimulation via TLR4, although this increase might be non-specific
Disturbance reduces the differentiation of mycorrhizal fungal communities in grasslands along a precipitation gradient
Given that mycorrhizal fungi play key roles in shaping plant communities, greater attention should be focused on factors that determine the composition of mycorrhizal fungal communities and their sensitivity to anthropogenic disturbance. We investigate changes in arbuscular mycorrhizal (AM) fungal community composition across a precipitation gradient in North American grasslands as well as changes occurring with varying degrees of site disturbance that have resulted in invasive plant establishment. We find strong differentiation of AM fungal communities in undisturbed remnant grasslands across the precipitation gradient, whereas communities in disturbed grasslands were more homogeneous. These changes in community differentiation with disturbance are consistent with more stringent environmental filtering of AM fungal communities in undisturbed sites that may also be promoted by more rigid functional constraints imposed on AM fungi by the native plant communities in these areas. The AM fungal communities in eastern grasslands were particularly sensitive to anthropogenic disturbance, with disturbed sites having low numbers of AM fungal operational taxonomic units (OTUs) commonly found in undisturbed sites, and also the proliferation of AM fungal OTUs in disturbed sites. This proliferation of AM fungi in eastern disturbed sites coincided with increased soil phosphorus availability and is consistent with evidence suggesting the fungi represented by these OTUs would provide reduced benefits to native plants. The differentiation of AM fungal communities along the precipitation gradient in undisturbed grasslands but not in disturbed sites is consistent with AM fungi aiding plant adaptation to climate, and suggests they may be especially important targets for conservation and restoration in order to help maintain or re-establish diverse grassland plant communities.This work was supported by Strategic Environmental Research and Development Program (SERDP) grant RC-2330 to J. D. BeverNational Science Foundation grant DEB-1556664 to J. D. Beve
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