Competition and Innovation: Evidence from Financial Services

In this paper we seek to contribute to the literature on competition and innovation by focusing on individual firms within the U.S. banking industry in the period 1984-2004. We measure innovation by estimating technology gaps and find evidence of an inverted-U relationship between competition and the technology gaps in banking. This finding is robust over several different specifications and is consistent with theoretical and empirical work by Aghion, Bloom, Blundell, Griffith, and Howitt (2005b). The optimal amount of innovation requires a slightly positive mark up. Also, we find that the U.S. banking industry as a whole has consolidated beyond this optimal innovation level and that state-level interstate banking deregulation has lowered innovation.competition, innovation, stochastic frontier analysis, technology gap ratio, banking

A Fallacy of Division: The Failure of Market Concentration as a Measure of Competition in U.S. Banking

Empirical literature and related legal practice using concentration as a proxy for competition measurement are prone to a fallacy of division, as concentration measures are appropriate for perfect competition and perfect collusion but not intermediate levels of competition. Extending the classic Cournot-type competition model of Cowling and Waterson (1976) and Cowling (1976) used to derive the Hirschman-Herfindahl Index (HHI) of market concentration, we propose an adaptation of this model that allows collusive rents for all, none, or some of the firms in a market. Application of our model to data for U.S. commercial banks in the period 1984-2004 confirms that concentration measures are unreliable competition metrics. While collusion is prevalent in the banking industry at the state level, the critical market shares at which market power is achieved, rents earned from collusion, and collusive concentration levels vary widely across states. These and other results lead us to conclude that a fallacy of division exists in concentration-based competition tests.SCP hypothesis, competition, Cournot, conjectural variation, efficiency hypothesis

Boron concentrations and isotopic compositions in methane-derived authigenic carbonates : constraints and limitations in reconstructing formation conditions

The work is supported by Norwegian Research Council through the schemes PETROMAKS2-NORCRUST (grant number 255150 ) and Centre for Arctic Gas Hydrate, Environment and Climate (CAGE grant number 223259 ) as well as Lundin Norway AS. Cruise MSM57-1/-2 was funded by the German Research Foundation (DFG), the Research Center/Excellence Cluster “The Ocean in the Earth System” at MARUM–Center for Marine and Environmental Sciences, University of Bremen and funds from CAGE.The boron content and isotopic composition (δ11B), of marine carbonates have the potential to constrain CO2 chemistry during carbonate growth conditions. However, obtaining and interpreting boron compositions from authigenic carbonates in geological archives present several challenges that may substantially limit their application. In particular, contamination from non-carbonate phases during sample preparation must be carefully avoided, and a variety of controls on boron composition during authigenic growth conditions must be evaluated. To advance understanding of the use and limitations of boron in authigenic carbonates, we present data and modelling results on methane-derived authigenic carbonate (MDAC), a by-product of microbially mediated anaerobic oxidation of methane, taken from three cold seep sites along the Norwegian margin. We present a novel sequential leaching method to isolate the boron signals from the micritic (Mg-calcite) and cavity-filling (aragonitic) MDAC cements in these complex multi-phase samples. This method successfully minimizes contamination from non-carbonate phases. To investigate the factors that could potentially contribute to the observed boron signals, we construct a numerical model to simulate the evolution of MDAC δ11B and B/Ca ratios over its growth history. We show that diagenetic fluid composition, depths of precipitation, the physical properties of sediments (such as porosity), and mineral surface kinetics all contribute to the observed boron compositions in the different carbonate cements. While broad constraints may be placed on fluid composition, the multiple competing controls on boron in these diagenetic settings limit the ability to place unique solutions on fluid CO2 chemistry using boron in these authigenic carbonates.Publisher PDFPeer reviewe

Band structure in classical field theory

Stability and instability bands in classical mechanics are well-studied in connection with systems such as described by the Mathieu equation. We examine whether such band structure can arise in classical field theory in the context of an embedded kink in 1+1 dimensions. The static embedded kink is unstable to perturbations but we show that if the kink is dynamic it can exhibit stability in certain parameter bands. Our results are relevant for estimating the lifetimes of various embedded defects and, in particular, loops of electroweak Z-string.Comment: 6 pages, 4 fig. Reference added, Fig. 3 updated with improved numerical code, minor comments added. Version to be published in Phys. Rev.

Recent developments in organoboron chemistry - old dogs, new tricks

Organoboron reagents have been synonymous with organic chemistry for over half a century and continue to see widespread application today; for example, classic reactions such as hydroboration and Suzuki-Miyaura cross-coupling are regularly practiced throughout the chemical community. In particular, applications of organoboron compounds have underpinned pharmaceutical and agrochemical development on both discovery and process scales for decades. Although it is noteworthy that these seminal reactions have stood the test of time, continually increasing pressure to improve efficiency in chemical synthesis demands innovation. Over the past few years, through an explosion in the number of new methods for the installation and manipulation of organoboron functional groups, as well as the understanding of their mechanistic operation, organoboron chemistry has risen to this challenge

Structural, Magnetic and Transport Properties of B-Site Substituted Perovskite La0.7Sr0.3MnO3

In this chapter, in order to understand the structural related magnetic and transport properties of B site substituted perovskites La0.7Sr0.3MnO3 (LSMO), we have systematically investigated the effects of replacing some of the Mn with nonmagnetic elements Ti, Zr, Cu, Al, Zn and magnetic elements Co, Ni, Cr, Fe. The structural, magnetic and electrical phase transitions and transport properties of these compounds were investigated by neutron diffraction, magnetization and electric resistivity measurements

Estimates of economic and environmental damages from tipping points cannot be reconciled with the scientific literature

Peer reviewe

Long-Ranged Correlations in Sheared Fluids

The presence of long-ranged correlations in a fluid undergoing uniform shear flow is investigated. An exact relation between the density autocorrelation function and the density-mometum correlation function implies that the former must decay more rapidly than $1/r$, in contrast to predictions of simple mode coupling theory. Analytic and numerical evaluation of a non-perturbative mode-coupling model confirms a crossover from $1/r$ behavior at ''small'' $r$ to a stronger asymptotic power-law decay. The characteristic length scale is $\ell \approx \sqrt{\lambda_{0}/a}$ where $$ is the sound damping constant and $a$ is the shear rate.Comment: 15 pages, 2 figures. Submitted to PR

Risk of pelvic inflammatory disease in relation to chlamydia and gonorrhea testing, repeat testing, and positivity: A population-based cohort study

Background: There is uncertainty around whether the risks of pelvic inflammatory disease (PID) differ following Chlamydia trachomatis (chlamydia) and Neisseria gonorrhoeae (gonorrhea) infection. We quantified the risk of PID associated with chlamydia and gonorrhea infection and subsequent repeat infections in a whole-population cohort. Methods: A cohort of 315123 Western Australian women, born during 1974–1995, was probabilistically linked to chlamydia and gonorrhea testing records and to hospitalizations and emergency department presentations for PID from 2002 to 2013. Time-updated survival analysis was used to investigate the association between chlamydia and gonorrhea testing, and positivity, and risk of PID. Results: Over 3199135 person-years, 120748 women had pathology test records for both chlamydia and gonorrhea, 10745 chlamydia only, and 653 gonorrhea only. Among those tested, 16778 (12.8%) had ≥1 positive chlamydia test, 3195 (2.6%) ≥1 positive gonorrhea test, and 1874 (1.6%) were positive for both. There were 4819 PID presentations (2222 hospitalizations, 2597 emergency presentations). Adjusting for age, Aboriginality, year of follow-up, health area, and socioeconomic status, compared to women negative for chlamydia and gonorrhea, the relative risk (adjusted incidence rate ratio) of PID was 4.29 (95% confidence interval [CI], 3.66–5.03) in women who were both chlamydia and gonorrhea positive; 4.54 (95% CI, 3.87–5.33) in those only gonorrhea positive; and 1.77 (95% CI, 1.61–1.94) in those only chlamydia positive. Conclusions: Gonorrhea infection conferred a substantially higher risk than chlamydia of hospitalization or emergency department presentation for PID. The emergence of gonorrhea antimicrobial resistance may have a serious impact on rates of PID and its associated reproductive health sequelae