Ultraviolet and X-ray variability of NGC 4051 over 45 days with XMM-Newton and Swift

We analyse 15 XMM-Newton observations of the Seyfert galaxy NGC 4051 obtained over 45 days to determine the ultraviolet (UV) light curve variability characteristics and search for correlated UV/X-ray emission. The UV light curve shows variability on all time scales, however with lower fractional rms than the 0.2-10 keV X-rays. On days-weeks timescales the fractional variability of the UV is Fvar ~ 8%, and on short (~ hours) timescales Fvar ~ 2%. The within-observation excess variance in 4 of the 15 UV observations was found be much higher than the remaining 11. This was caused by large systematic uncertainties in the count rate masking the intrinsic source variance. For the four "good" observations we fit an unbroken power-law model to the UV power spectra with slope -2.0 +/- 0.5. We compute the UV/X-ray Cross-correlation function for the "good" observations and find a correlation of ~ 0.5 at time lag of ~ 3 ks, where the UV lags the X-rays. We also compute for the first time the UV/X-ray Cross-spectrum in the range 0-28.5 ks, and find a low coherence and an average time lag of ~ 3 ks. Combining the 15 XMM-Newton and the Swift observations we compute the DCF over +/-40 days but are unable to recover a significant correlation. The magnitude and direction of the lag estimate from the 4 "good" observations indicates a scenario where ~ 25 % of the UV variance is caused by thermal reprocessing of the incident X-ray emission.Comment: 11 pages, 8 figures. Accepted for publication in MNRA

The flux-dependent X-ray time lags in NGC 4051

We present an analysis of the X-ray time lags for the highly variable Seyfert 1 galaxy NGC 4051, based on a series of XMM-Newton observations taken in 2009. We investigate the Fourier frequency dependent time lags in the light curves between the 0.3--1.0 keV and 2.0--5.0 keV energy bands as a function of source flux, including simultaneous modelling of the resulting lag-frequency spectra. We find the shape of the lag-frequency spectra to vary significantly and systematically with source flux. We model the lag-frequency spectra using simple transfer functions, and find that two time lag components are required, one in each energy band. The simplest acceptable fits have only the relative contribution of the lagged component in the hard band varying with flux level, which can be associated with changes in the energy spectrum. We discuss the interpretation of these results in terms of the currently popular models for X-ray time lags.Comment: 9 pages, 4 figures. Accepted for publication in MNRA

Taxes and quality: A market-level analysis

Aconventional assumption of product homogeneity when the commodity of interest is actually heterogeneous will lead to errors in an analysis of the incidence of policies, such as taxes. In this article, an equilibrium displacement model is used to derive analytical solutions for price, quantity, and quality effects of ad valorem and per unit taxes. The results show how parameters determine the effects of tax policies on quality. The potential for tax-induced distortions in quality, and the distributive consequences of those distortions, are illustrated in a case study of the market for Australian wine.Resource /Energy Economics and Policy,

STATE TRADING VERSUS EXPORT SUBSIDIES: THE CASE OF CANADIAN WHEAT

Canada and the United States have used different trade policies to support their wheat industries. Canada conferred sole export powers to the Canadian Wheat Board, allowing it to price discriminate among markets. The U.S. government has funded transfers to its wheat producers from taxpayers, instead, through export subsidies. This study compares these two ways of supporting producers in terms of their transfer efficiency and overall deadweight losses, the incidence on different domestic interest groups, and their consequences for third party traders. In the analysis we consider the implications of market power of wheat marketing firms for the comparison of policy alternatives in the context of the Canadian wheat industry.International Relations/Trade,

Creation and Analysis of Checklists to Improve Raquet Stringing Performance in Tennis Warehouse

Tennis Warehouse has a need to increase the supply of strung racquets and man hours to complete these strung racquets over the course of a year. That is, the demand can be increased by up to 4 times its average load during certain hectic parts of the year (professional tournaments, holidays, and competitive seasons). Not meeting this demand can lead to upset customers, unnecessary waste and replacing of rushed items and shipping costs, and a discouraged customer service representative workforce. The objective of this project is to use a set of checklists to address this problem and attempt to increase the amount of time allocated to stringing racquets by eliminating wastes, retraining employees, and providing a safe and efficient workplace for employees to work in. The checklists were created in accordance with national standard safety procedures, ergonomic justification, and lean manufacturing and process improvement tenants. Each checklist took into account the amount of time each check would save in a mock simulation. This simulation took into account many factors including the amount of time it would take to retrain an employee on certain aspects, the amount a broken part (racquet or string) would cost, the amount of time and money an injury or sickness would cost the company, and the time it takes for an employee to complete a part (string a racquet). Best assumptions were made in discussion with employees about other aspects, such as defective parts per month, the amount it takes for set up and shut down of a work station, and time spent on running through these checklists. The simulated improvements made as a result of the checklist turned to address up to three quarters of the increased demand. Although this is a rough estimate based on the few assumptions were made, this simulation proves to provide a massive improvement to the problem of increased demand. It also serves to provide a justification for Tennis Warehouse’s use of checklists as a possible tool to use in the future to satisfy demand. The overall results served to back up and provide extreme evidence of checklist effectiveness not only in a retailer like Tennis Warehouse, but possibly has uses in other fields such as medical, automotive manufacturing, and construction. Recommendations for Tennis Warehouse are to use the provided checklist as an example and not only utilize them in everyday operations, but to record the effects over a couple months to evaluate their value further

Levy-funded research choices by producers and society

Commodity levies are used increasingly to fund producer collective goods such as research and promotion. In the present paper we examine theoretical relationships between producer and national benefits from levy‐funded research, and consider the implications for the appropriate rates of matching government grants, applied with a view to achieving a closer match between producer and national interests. In many cases the producer and national optima coincide. First, regardless of the form of the supply shift, when product demand is perfectly elastic, or all the product is exported, domestic benefits and costs of levy‐funded research all go to producers and they have appropriate incentives. Second, if research causes a parallel supply shift, the producer share of research benefits is the same as their share of costs of a levy, and their incentives are compatible with national interests. In such cases, a matching grant would cause an over‐investment in research from a national perspective. However, if demand is less than perfectly elastic, and research causes a pivotal supply shift, the producer share of benefits is smaller than their share of costs of the levy, and they will under‐invest in research from a national point of view. A matching grant can be justified in such cases, however the magnitude of the optimal grant is sensitive to market conditions.Research and Development/Tech Change/Emerging Technologies,

WHEAT DISPUTES UNDER NAFTA

International Relations/Trade,

Demand Enhancement through Food-Safety Regulation: Benefit-Cost Analysis of Collective Action in the California Pistachio Industry

Food safety shocks can threaten the health of consumers, create havoc within an industry and result in severe losses to producers. Governments often attempt to enhance food safety by mandating standards and inspection of food products to supplement the voluntary efforts by private firms. This paper assesses a form of collective action that falls between typical government mandates and purely private action. The California pistachio industry recently established a U.S. federal marketing order. This order sets quality standards and requires inspection and certification, aiming to reduce the likelihood of dangerous or poor quality pistachios being sold to consumers and to provide some quality assurance to consumers. Simulation results indicate that, across the full range of parameters used in the analysis, the benefit-cost analysis was always favorable to the new policy. Continuing work is extending the analysis to account for some particular features of the pistachio industry, to consider alternative policies, and to draw inferences for the application of similar policies to other California specialty crops.Food Safety, Collective Action, Specialty Crops, Government Regulation, Marketing Orders, Pistachios, Food Consumption/Nutrition/Food Safety, Q18, Q13, I18, H4,

ECONOMIC IMPACTS OF MANDATED GRADING AND TESTING TO AVOID A NEGATIVE FOOD SAFETY EVENT: EX ANTE ANALYSIS OF THE FEDERAL MARKETING ORDER FOR PISTACHIOS

The California pistachio industry led an initiative to establish a federal marketing order, which mandates quality standards and an inspection program to assure food safety and consistency in the quality of California pistachios. We develop a stochastic dynamic simulation model of the pistachio market to investigate quantitatively the likely effects of such collective action enforced by government mandates. Simulation results indicate that, across the full range of parameters used in the analysis, the benefit-cost analysis was always favorable to the proposed policy. The measured benefits to producers, the nation, or the world always well exceeded the corresponding measure of costs, typically by many times.Food Consumption/Nutrition/Food Safety,

Industry-mandated testing to improve food safety: the new US marketing order for pistachios

Food safety shocks can threaten the health of consumers, create havoc within an industry and result in severe losses to producers. Governments often attempt to aid food safety by mandating standards and inspection of food products to supplement the efforts by private firms and industries. This article assesses a form of collective action that falls between typical government mandates and purely private action. The California pistachio industry recently established a U.S. federal marketing order, which sets quality standards and inspection to reduce the likelihood of dangerous or poor quality pistachios. Simulation results indicate that, across the full range of parameters used in the analysis, the benefit-cost analysis was always favorable to the new policy. In the case of California pistachios, collective action is likely to be a helpful tool to ensure a safe product and increase benefits to producers and consumers.food safety, food scare, collective action, marketing orders, pistachios, public good, food regulations, cost-benefit analysis, Agribusiness, Food Consumption/Nutrition/Food Safety,