The Effect of Electronic Commerce on Geographic Trade and Price Variance in a Business-to-Business Market

Imbalances in supply and demand often cause the price for the same good to vary across geographic locations. Economic theory suggests that if the price differential is greater than the cost of transporting the good between locations, then buyers will shift demand from high-price locations to lowprice locations, while sellers will shift supply from low-price locations to high-price locations. This should make prices more uniform and cause the overall market to adhere more closely to the “law of one price.” However, this assumes that traders have the information necessary to shift their supply/demand in an optimal way. We investigate this using data on over 2 million transactions in the wholesale used vehicle market from 2003 to 2008. This market has traditionally consisted of a set of non-integrated regional markets centered on market facilities located throughout the United States. Supply / demand imbalances and frictions associated with trading across distance created significant geographic price variance for generally equivalent vehicles. During our sample period, the percentage of transactions conducted electronically in this market rose from approximately 0% to approximately 20%. We argue that the electronic channel reduces buyers’ information search costs and show that buyers are more sensitive to price and less sensitive to distance when purchasing via the electronic channel than via the traditional physical channel. This causes buyers to be more likely to shift demand away from a nearby facility where prices are high to a more remote facility where prices are low. We show that these “cross-facility” demand shifts have led to a 25% reduction in geographic price variance during the time frame of our sample. We also show that sellers are reacting to these market shifts by becoming less strategic about vehicle distribution, given that vehicles are increasingly likely to fetch a similar price regardless of where they are sold

The Market is Flat (or is it?) The Effect of Electronic Trading on Buyer Reach, Geographic Transaction Activity and Geographic Price Variance

We analyze how increased use of electronic channels affects geographic price variance by enabling buyers to shift demand across locations. Using data from the wholesale automotive market, we find that buyers use the reach of the electronic channels to shift purchases from highprice to low-price locations. This “arbitrage” reduces the variance of market prices, but not their means. Further, these relationships weaken with distance, due to transportation costs. The study contributes to the literature on how electronic trading affects geographic trade and price dispersion by: a) considering the role of geographic location in price dispersion, b) observing the behavioral mechanism (buyer arbitrage across locations) that leads to lower price dispersion, c) analyzing dispersion when prices are determined by auction rather than fixed price, and d) examining how reduced buyer search costs have led to lower price dispersion throughout the entire market, as opposed to only the online or offline components

Shear thickening in densely packed suspensions of spheres and rods confined to few layers

We investigate confined shear thickening suspensions for which the sample thickness is comparable to the particle dimensions. Rheometry measurements are presented for densely packed suspensions of spheres and rods with aspect ratios 6 and 9. By varying the suspension thickness in the direction of the shear gradient at constant shear rate, we find pronounced oscillations in the stress. These oscillations become stronger as the gap size is decreased, and the stress is minimized when the sample thickness becomes commensurate with an integer number of particle layers. Despite this confinement-induced effect, viscosity curves show shear thickening that retains bulk behavior down to samples as thin as two particle diameters for spheres, below which the suspension is jammed. Rods exhibit similar behavior commensurate with the particle width, but they show additional effects when the thickness is reduced below about a particle length as they are forced to align; the stress increases for decreasing gap size at fixed shear rate while the shear thickening regime gradually transitions to a Newtonian scaling regime. This weakening of shear thickening as an ordered configuration is approached contrasts with the strengthening of shear thickening when the packing fraction is increased in the disordered bulk limit, despite the fact that both types of confinement eventually lead to jamming.Comment: 21 pages, 14 figures. submitted to the Journal of Rheolog

The Effect of Electronic Commerce on Geographic Trade and Price Variance in a Business-to-Business Market

Imbalances in supply and demand often cause the price for the same good to vary across geographic locations. Economic theory suggests that if the price differential is greater than the cost of transporting the good between locations, then buyers will shift demand from high-price locations to lowprice locations, while sellers will shift supply from low-price locations to high-price locations. This should make prices more uniform and cause the overall market to adhere more closely to the “law of one price.” However, this assumes that traders have the information necessary to shift their supply/demand in an optimal way. We investigate this using data on over 2 million transactions in the wholesale used vehicle market from 2003 to 2008. This market has traditionally consisted of a set of non-integrated regional markets centered on market facilities located throughout the United States. Supply / demand imbalances and frictions associated with trading across distance created significant geographic price variance for generally equivalent vehicles. During our sample period, the percentage of transactions conducted electronically in this market rose from approximately 0% to approximately 20%. We argue that the electronic channel reduces buyers’ information search costs and show that buyers are more sensitive to price and less sensitive to distance when purchasing via the electronic channel than via the traditional physical channel. This causes buyers to be more likely to shift demand away from a nearby facility where prices are high to a more remote facility where prices are low. We show that these “cross-facility” demand shifts have led to a 25% reduction in geographic price variance during the time frame of our sample. We also show that sellers are reacting to these market shifts by becoming less strategic about vehicle distribution, given that vehicles are increasingly likely to fetch a similar price regardless of where they are sold

Evaluation of electropolished stainless steel electrodes for use in DC high voltage photoelectron guns

DC high voltage photoelectron guns are used to produce polarized electron beams for accelerator-based nuclear and high-energy physics research. Low-level field emission (similar to nA) from the cathode electrode degrades the vacuum within the photogun and reduces the photoelectron yield of the delicate GaAs-based photocathode used to produce the electron beams. High-level field emission (\u3e mu A) can cause significant damage the photogun. To minimize field emission, stainless steel electrodes are typically diamond-paste polished, a labor-intensive process often yielding field emission performance with a high degree of variability, sample to sample. As an alternative approach and as comparative study, the performance of electrodes electropolished by conventional commercially available methods is presented. Our observations indicate the electropolished electrodes exhibited less field emission upon the initial application of high voltage, but showed less improvement with gas conditioning compared to the diamond-paste polished electrodes. In contrast, the diamond-paste polished electrodes responded favorably to gas conditioning, and ultimately reached higher voltages and field strengths without field emission, compared to electrodes that were only electropolished. The best performing electrode was one that was both diamond-paste polished and electropolished, reaching a field strength of 18.7 MV/m while generating less than 100 pA of field emission. The authors speculate that the combined processes were the most effective at reducing both large and small scale topography. However, surface science evaluation indicates topography cannot be the only relevant parameter when it comes to predicting field emission performance. (C) 2015 American Vacuum Society

What could a strengthened right to health bring to the post-2015 health development agenda?: interrogating the role of the minimum core concept in advancing essential global health needs.

BACKGROUND: Global health institutions increasingly recognize that the right to health should guide the formulation of replacement goals for the Millennium Development Goals, which expire in 2015. However, the right to health's contribution is undercut by the principle of progressive realization, which links provision of health services to available resources, permitting states to deny even basic levels of health coverage domestically and allowing international assistance for health to remain entirely discretionary. DISCUSSION: To prevent progressive realization from undermining both domestic and international responsibilities towards health, international human rights law institutions developed the idea of non-derogable "minimum core" obligations to provide essential health services. While minimum core obligations have enjoyed some uptake in human rights practice and scholarship, their definition in international law fails to specify which health services should fall within their scope, or to specify wealthy country obligations to assist poorer countries. These definitional gaps undercut the capacity of minimum core obligations to protect essential health needs against inaction, austerity and illegitimate trade-offs in both domestic and global action. If the right to health is to effectively advance essential global health needs in these contexts, weaknesses within the minimum core concept must be resolved through innovative research on social, political and legal conceptualizations of essential health needs. SUMMARY: We believe that if the minimum core concept is strengthened in these ways, it will produce a more feasible and grounded conception of legally prioritized health needs that could assist in advancing health equity, including by providing a framework rooted in legal obligations to guide the formulation of new health development goals, providing a baseline of essential health services to be protected as a matter of right against governmental claims of scarcity and inadequate international assistance, and empowering civil society to claim fulfillment of their essential health needs from domestic and global decision-makers

Association Between Passive and Active Smoking and Incident Type 2 Diabetes in Women

OBJECTIVE: Accumulating evidence has identified a positive association between active smoking and the risk of diabetes, but previous studies had limited information on passive smoking or changes in smoking behaviors over time. This analysis examined the association between exposure to passive smoke, active smoking, and the risk of incident type 2 diabetes among women. RESEARCH DESIGN AND METHODS: This is a prospective cohort study of 100,526 women in the Nurses’ Health Study who did not have prevalent diabetes in 1982, with follow-up for diabetes for 24 years. RESULTS: We identified 5,392 incident cases of type 2 diabetes during 24 years of follow-up. Compared with nonsmokers with no exposure to passive smoke, there was an increased risk of diabetes among nonsmokers who were occasionally (relative risk [RR] 1.10 [95% CI 0.94–1.23]) or regularly (1.16 [1.00–1.35]) exposed to passive smoke. The risk of incident type 2 diabetes was increased by 28% (12–50) among all past smokers. The risk diminished as time since quitting increased but still was elevated even 20–29 years later (1.15 [1.00–1.32]). Current smokers had the highest risk of incident type 2 diabetes in a dose-dependent manner. Adjusted RRs increased from 1.39 (1.17–1.64) for 1–14 cigarettes per day to 1.98 (1.57–2.36) for ≥25 cigarettes per day compared with nonsmokers with no exposure to passive smoke. CONCLUSIONS: Our study suggests that exposure to passive smoke and active smoking are positively and independently associated with the risk of type 2 diabetes