Role Of Shocks Research Articles

Credit Market Shocks: Evidence From Corporate Spreads and Defaults

Several recent papers have found that exogenous shocks to spreads paid in corporate credit markets are a substantial source of macroeconomic fluctuations. An alternative explanation of the data is that spreads respond endogenously to expectations of future default. We use a simple model of bond spreads to derive sign restrictions on the impulse-response functions of a VAR that identify credit shocks in the bond market, and compare them to results from a benchmark recursive VAR. We find that credit market shocks cause a persistent decline in output, prices and policy rates. Historical decompositions clearly show the negative effect of adverse credit market shocks on output in the recent recession. The identified credit shocks are unrelated to exogenous innovations to monetary policy and measures of bond market liquidity, but are related to measures of risk compensation. In contrast to results found using the benchmark restrictions, our identified credit shocks account for relatively little of the variance of output. Our results are consistent with a role for shocks in financial crises, but also with a lesser but non-zero role in normal business fluctuations.

External Balance in Low Income Countries

This paper offers a coherent empirical analysis of the determinants of the real exchange rate, the current account, and the net foreign assets position in low income countries. The paper focuses on indicators specific to low income countries, such as the quality of policies and institutions, the special access to official external financing, and the role of shocks. In addition to more standard factors, we find that domestic financial liberalization is associated with higher current account balances and net foreign asset positions, while capital account liberalization is associated with lower current account balances and net foreign asset positions and with more appreciated real exchange rates. Negative exogenous shocks tend to raise (reduce) the current account in countries with closed (opened) capital accounts. Finally, foreign aid is progressively absorbed over time through net imports, and is associated with a more depreciated real exchange rate in the long-run.

Disruption of the C5a receptor gene increases resistance to acute Gram-negative bacteremia and endotoxic shock: Opposing roles of C3a and C5a

The host response to intravascular, Gram-negative bacteria includes profound immunologic, hematologic and physiologic changes. Numerous host defense mechanisms are activated by Gram-negative bacteria, including the complement system. Activation of the complement system leads to cleavage of C5 with subsequent generation of the C5a anaphylatoxin peptide. C5a mediates potent, proinflammatory activities by binding to the C5a receptor (C5aR, CD88). In this study, we report the targeted disruption of the murine C5aR gene (C5aR−/− mice) and define the role of the C5aR in a model of Gram-negative bacteremia. Following an intravenous infusion of heat-killed Escherichia coli, the C5aR−/− mice were completely protected from the mortality suffered by their wild-type littermates ( P < 0.001). The C5aR−/− mice were also significantly ( P = 0.008) more resistant to mortality following an intravenous infusion of purified E. coli endotoxin compared to the wild-type littermates. In addition, the C5aR−/− mice were resistant to the thrombocytopenia and hemoconcentration observed in wild-type animals. Lethality in the wild-type mice was reversed by pre-treatment with either the histamine antagonist diphenhydramine or triprolidine. The wild-type littermates were also rescued following pre-treatment with the basophil and mast cell-stabilizing agent – cromolyn sodium. Collectively, these data demonstrate that not only is the absence of the C5aR protective in E. coli bacteremia, but that C5aR-dependent histamine release plays a major role in shock induced by Gram-negative septicemia. Moreover, they provide additional in vivo evidence that C3a and C5a have divergent biological functions in Gram-negative bacteremia and shock.

New insights into the pathogenesis and treatment of anthrax toxin-induced shock

Inhalational Bacillus anthracis infection is a leading bioterrorist health threat in the US today. Lethal (LeTx) and edema toxin production are key to the virulent effects of this lethal bacteria. Recent insights into the structure and function of these toxins have increased the understanding of both the pathogenesis and treatment of anthrax. These are binary type toxins comprised of protective antigen necessary for their cellular uptake and either lethal or edema factors, the toxigenic moieties. Primary cellular receptors for protective antigen have been identified and the processing of the completed toxins clarified. Consistent with the ability of lethal factor to cleave mitogen activated protein kinase kinases, the evidence indicates that an excessive inflammatory response does not contribute to shock with LeTx. Rather, the immunosuppressive effects of LeTx could promote infection; however, direct endothelial dysfunction may have an important role in shock due to LeTx. Recent studies show that edema factor, a potent adenyl cyclase, may have a major role in shock during anthrax and that it may also be immunosuppresive. Therapies under development which target several steps in the cellular uptake and function of these two toxins have been effective in both in vitro and in vivo systems. Understanding how best to apply these agents in combination with conventional treatments should be a goal of future research.

European unemployment: the evolution of facts and ideas

In the 1970s, European unemployment started increasing. It increased further in the 1980s, to reach a plateau in the 1990s. It is still high today, although the average unemployment rate hides a high degree of heterogeneity across countries. The focus of researchers and policy makers was initially on the role of shocks. As unemployment remained high, the focus has progressively shifted to institutions. This paper reviews the interaction of facts and theories, and gives a tentative assessment of what we know and what we still do not know. — Olivier Blanchard

A New Hypothesis for Microvascular Inflammation in Shock and Multiorgan Failure: Self‐Digestion by Pancreatic Enzymes

Shock is accompanied by a severe inflammatory cascade in the microcirculation, the origin of which has been hypothesized in the past to be associated with specific mediators such as endotoxin, oxygen free radicals, nitric oxide, cytokines, and lipid products. But no intervention with clinical effectiveness has been derived from these ideas to date. The authors propose here a new hypothesis suggesting that degradative enzymes, synthesized in the pancreas as part of normal digestion, may play a central role in shock and multiorgan failure. These powerful enzymes have the ability to digest almost every biological material. Self-digestion (i.e. autodegradation) is prevented by compartmentalizing the fully activated degradative enzymes in the intestinal lumen by the mucosal barrier. In shock, maintenance of the mucosal barrier is impaired and it becomes permeable to pancreatic enzymes. Digestive enzymes thereby gain access to the wall of the intestine and initiate self-digestion of submucosal extracellular matrix proteins and interstitial cells. The process leads to generation and release of a host of strong inflammatory mediators. The authors hypothesize that inhibition of pancreatic enzymes in the lumen of tile intestine can serve to attenuate formation of these inflammatory mediators in ischemic tissues following hemorrhagic shock, and consequently prevent cell and tissue injury as well as multiorgan failure.

Reexamining the Consumption-Wealth Relationship: The Role of Model Uncertainty

In their influential work on the consumption-wealth relationship, Lettau and Ludvigson found that while consumption responds to permanent changes in wealth in the expected manner, most changes in wealth are transitory with no effect on consumption. We investigate the robustness of these results to model uncertainty using Bayesian model averaging. We find that there is model uncertainty with regard to the number of cointegrating vectors, the form of deterministic components, lag length, and whether the cointegrating residuals affect consumption and income directly. Whether this uncertainty has important implications depends on the researcher's attitude toward this economic theory used by Lettau and Ludvigson. If we work with their exact model, our findings are very similar. However, if we work with a broader set of models, we find that the exact magnitude of the role of permanent shocks is difficult to estimate precisely. Thus, although some support exists for the view that the role of shocks is small, we cannot rule out the possibility that they have a substantive effect on consumption.

European Unemployment: The Evolution of Facts and Ideas

In the 1970s, European unemployment started increasing. It increased further in the 1980s, to reach a plateau in the 1990s. It is still high today, although the average unemployment rate hides a high degree of heterogeneity across countries. The focus of researchers and policy makers was initially on the role of shocks. As unemployment remained high, the focus has progressively shifted to institutions. This paper reviews the interaction of facts and theories, and gives a tentative assessment of what we know and what we still do not know.

Shocks as causes of turnover: What they are and how organizations can manage them

Voluntary employee turnover is expensive. Companies that successfully retain the best and brightest employees save money and protect their intellectual capital. Traditional approaches to understanding turnover place accumulated job dissatisfaction as the primary antecedent to voluntary turnover. However, we show that precipitating events, or shocks, more often are the immediate cause of turnover. Using data from more than 1,200 “leavers,” we describe the nature, content, and role of shocks in turnover decisions. We then provide strategies to help organizations manage shocks, and thereby control turnover. © 2005 Wiley Periodicals, Inc.

The Role of Shocks in Employee Turnover*

This paper reports the findings from a recent study of nurse leavers at eight large hospitals in the National Health Service (NHS) of England and Wales. The study develops and extends an influential theory of employee turnover by describing how for some leavers a single, jarring event or shock triggers the decision to quit. By elaborating on the nature of shocks for this sample of 352 nurse leavers, the paper allows for improved understanding of nursing turnover and thus offers an example of relevant management research. The analysis of shock illustrates how conventional research methodologies can lead to a distorted picture of turnover. This has wider implications, both for any organization wishing to manage turnover effectively and for future research. The paper adds to the limited body of empirical analysis on actual leavers, thereby contributing to an ongoing methodological debate concerning the use of proxy variables. By highlighting flaws in the dominant methodology used to study turnover, the paper offers an example of management research that is also rigorous, and thus ‘pragmatic’.

From Perinet to Jelinek: Viennese Theatre in Its Political and Intellectual Context by W. E. Yates , Allyson Fiddler , John Warren (review)

552 Reviews (p. 184). The contrast with Gay's Beggar's Opera is well made, not always to Brecht's advantage, so that the statement that this 'may be seen as the highpoint of Brecht's career' (p. 192) is surprising. Ronald Speirs examines Brecht's Mutter Courage und ihre Kinder as important for the establishment of the Berliner Ensemble, for its role in internal cultural politics in the GDR, and as a landmark in Brecht's own development as a producer of stageplays . Its dialectical presentation of major social themes and events relevant to the late twentieth century emphasizes social contradictions set at the start of a series of wars that Brecht believed to result from capitalism. Mother Courage's position is revealed as both tragic and ironic, supported by visual and verbal rhetoric that is both meaningful and precise. Michael Minden considers Peter Weiss's Marat/'Sade as a turning point in Weiss's development, deliberately complex and confusing in the use of time, ofthe authority of Sade, and of its network of ideas. Reviewing interpretations that stress its presenta? tion ofpotential freedom and its revelation of primitive energies, its immediate impact on the audience and its closeness to the theatre of cruelty,Minden adds his reflections on the role of shock in response to the demands of modern audiences saturated with media effects. 'The mixture of radical socialist politics and radical sex is irresistible' (p. 222). The play is finallypresented as a happening. Ben Morgan introduces his discussion of Jelinek's Krankheit oder moderne Frauen by considering at some length its predecessor, Handke's Publikumsbeschimpfung.Selfdeconstruction and an anti-theatrical style are identified in Jelinek's earlier dramas. In Krankheit 'theatre has been, as it were, broken down into its component parts' and the audience are left with the work of recombining them (p. 242). The play is also seen as a reaction to the gender imbalance of dramatic tradition. By concentrating mainly on important features that made each drama into a land? mark, these essays offerconsiderable help to students. Although they present no new research findings, their detailed comments should invite further discussion and be quoted to advantage in essays, dissertations, and lecture courses. The collection may then itself become a valued landmark. Mellen University, Iowa Brian Keith-Smith From Perinet toJelinek: Viennese Theatre in its Political and Intellectual Context. Ed. by W. E. Yates, Allyson Fiddler, and John Warren. (British and Irish Stud? ies in German Language and Literature, 28) Oxford, Bern, etc: Peter Lang. 290 pp. 2001. SWF72. ISBN 3-906766-80-2 (pbk). Although the title and the chronological arrangement of these papers may suggest a survey of the familiar Viennese theatrical canon, we in fact get something more unusual: an account not only of mainline theatre but also of associated forms such as cabaret and monodrama, with attention to such institutional spects of theatre as censorship, criticism, and even fireprecautions. The central dramatic tradition is represented by essays on Grillparzer (Hans Holler and F. J. Lamport, the latter comparing the mythic drama Libussa with Hebbel's Die Nibelungen), welcome appreciations of plays by the once celebrated, now underrated Karl Schonherr and Max Mell (by Emma Smith and Judith Beniston respectively), and the Jedermann theme as revived by Hofmannsthal and updated by Felix Mitterer (Ulrike Tanzer), while recent drama is also treated in essays on monologues and silence in Bernhard's Heldenplatz (Stefan Krammer) and on sport and violence in Jelinek 's Ein Sportstiick (Allyson Fiddler). The emphasis is transferredto reception, and thus to the interaction between dramatist and public, in essays on Raimund's MoisasursZauberfluchby Ian Roe (who notes the deficiencies ofcurrent Raimund research, in MLRy 99.2, 2004 553 contrast to the Nestroy boom), and on the unfriendly Viennese reaction to Horvath's critical Volksstiicke(Louise Adey Huish), while John Warren provides a masterly brief survey of theatrical criticism between the wars, giving particular praise to David Josef Bach. W. E. Yates's essay on 'The Rise and Fall ofthe One-Act Play' attends especially to the financial circumstances and public preferences that help explain the popularity of one-acters from the 1850s to the 1880s and their revival by Modernists...

Antioxidant-independent ascorbate enhancement of catecholamine-induced contractions of vascular smooth muscle.

Ascorbate reduces the oxidation rate of catecholamines and, by an independent mechanism, enhances rabbit aortic ring contractions initiated by catecholamines. The largest significantly different fractional increases in force produced by ascorbate enhancement of norepinephrine (NE), epinephrine, phenylpropanolamine (PPA), and ephedrine (Eph) are 5.5, 1.8, 1.6, and 1.3 times, respectively. In physiological salt solutions bubbled with 95% O(2) at 37 degrees C, NE, PPA, and Eph have oxidation rate constants of 1.24, 247, and 643 h, respectively. Ascorbate significantly enhances 100 nM NE contractions by at least twofold at all ascorbate concentrations >15 microM, including the entire physiological range of 40-100 microM. Ascorbate preloading and washout followed by NE exposure produces significantly greater contractions than NE without ascorbate preloading but significantly lower than NE simultaneously with ascorbate. Ascorbate does not enhance K(+)- or angiotensin II-induced contractions. Ascorbate enhancement of catecholamine contractions occurs in addition to the reduction in oxidation rate, because the increases in force occur faster than oxidation can occur, the increases occur with compounds that have negligible oxidation rates, and the increases occur when ascorbate and NE are not physically present together. These results are consistent with ascorbate acting on the adrenergic receptor. Ascorbate may play a role in shock and asthma treatments and potentiate the cardiovascular health consequences of PPA and Eph (Ephedra).

Complement plays an essential role in shock following intestinal ischaemia in rats.

Intestinal ischaemia lasting more than 30 min in rats causes fatal systemic shock. Systemic shock was suppressed by preadministration of cobra venom factor (CVF), which reduced the serum complement to less than 5% of the normal level, indicating that complement is involved in the syndrome. After complement activation, anaphylatoxins such as C3a and C5a are generated, and their activity is restricted by carboxypeptidases which remove C-terminal arginine from such bioactive peptides. As expected, preadministration of a carboxypeptidase inhibitor enhanced the systemic shock induced by the intestinal ischaemia. However, when the complement level was suppressed by CVF treatment, no fatal systemic shock was induced by the intestinal ischaemia even with preadministration of the carboxypeptidase inhibitor. These results indicate that complement plays a crucial role in systemic shock induced by intestinal ischaemia, and that anaphylatoxins generated by the complement activation should be involved in induction of the shock syndrome.

Application of a Self‐consistent Thermal Balance and Radiative Transfer Model to Study the Observed 183 GHz Masing Emission from Water in Orion

A detailed theoretical model for the thermal balance, chemistry, and radiative transfer within centrally heated, quiescent molecular cloud cores (Doty & Neufeld) is used to predict the properties of the 183 GHz 313-220 rotational masing transition of para-H2O in Orion. The model suggests weak masing for this transition, with maximum negative optical depths at line center in the range 0.12 < -τmax < 0.34. The ensuing maser gain is a nonmonotonic function of the water abundance, peaking at intermediate values. The model results are compared with the observations of Cernicharo et al. for this transition. Fits to their data suggest there are two components: a narrow (Δv = 2.47 km s-1) feature consistent with previous studies of relatively quiescent gas and a broad (Δv = 10.5 km s-1) feature consistent with the well-known shocks in Orion. Both chemical and uniform abundance models are compared with these data. The gas-phase chemical models are inconsistent with the observed constraints on the peak temperature and total source luminosity—confirming that the role of shock and/or grain mantle chemistry is important. If uniform abundances are assumed, the water abundance is conservatively constrained to the range 3 × 10-6 < x(H2O) < 3 × 10-5.

The Role of Shocks and Institutions in the Rise of European Unemployment: the Aggregate Evidence

Two key facts about European unemployment must be explained: the rise in unemployment since the 1960s, and the heterogeneity of individual country experiences. While adverse shocks can potentially explain much of the rise in unemployment, there is insufficient heterogeneity in these shocks to explain cross-country differences. Alternatively, while explanations focusing on labour market institutions explain current heterogeneity well, many of these institutions pre-date the rise in unemployment. Based on a panel of institutions and shocks for 20 OECD nations since 1960 we find that the interaction between shocks and institutions is crucial to explaining both stylised facts.

Pancreatic Enzymes May Play Role in Shock

Pancreatic Enzymes May Play Role in Shock

Resolving Indeterminacy in Dynamic Settings: The Role of Shocks*

This paper shows that the phenomenon of multiple equilibria can be fragile to the introduction of aggregate shocks. We examine a standard dynamic model of sectoral choice with external increasing returns. Without shocks, the outcome is indeterminate: there are multiple rational expectations equilibria. We then introduce shocks in the form of a parameter that follows a Brownian motion and affects relative productivity in the two sectors. We assume that the parameter can reach values at which working in either sector becomes a dominant choice. A unique equilibrium emerges; for any path of the random parameter, there is a unique path that the economy must follow. There is no role for multiple, self-fulfilling prophecies or sunspots.

What do we know about Macroeconomics that Fisher and Wicksell did not

The answer to the question in the title is: A lot. In this essay, I argue that the history of macroeconomics during the 20th century can be divided into three epochs: Pre-1940. A period of exploration, where macroeconomics was not macroeconomics yet, but monetary theory on one side, business cycle theory on the other. A period during which all the right ingredients, and quite a few more, were developed. But also a period where confusion reigned, because of the lack of an integrated framework. From 1940 to 1980. A period of consolidation. A period during which an integrated framework was developed – starting with the IS-LM, all the way to dynamic general equilibrium models – and used to clarify the role of shocks and propagation mechanisms in fluctuations. But a construction with an Achille's heel, namely too casual a treatment of imperfections, leading to a crisis in the late 1970s. Since 1980. A new period of exploration, focused on the role of imperfections in macroeconomics, from the relevance of nominal price setting, to incompleteness of markets, to asymmetric information, to search and bargaining in decentralized markets. Exploration often feels like confusion. But behind it may be one of the most productive periods of research in macroeconomics.

CD14 Plays No Major Role in Shock Induced by Staphylococcus aureus but Down-Regulates TNF-α Production

Abstract Recent in vitro studies have suggested that CD14, a major receptor for LPS, may also be a receptor for cell wall components of Gram-positive bacteria and thus play a role in Gram-positive shock. To analyze the in vivo role of CD14 in responses to Gram-positive bacteria, CD14-deficient and control mice were injected with Staphylococcus aureus, and the effects on lethality, bacterial clearance, and production of cytokines were analyzed. Survival of CD14-deficient and control mice did not differ significantly after administration of various doses of either unencapsulated or encapsulated S. aureus; furthermore, mice in both groups displayed similar symptoms of shock. In addition, inflammatory cytokines such as TNF-α and IL-6 were readily detectable in the serum of CD14-deficient mice injected with live or antibiotic-killed S. aureus. Surprisingly, the serum concentration of TNF-α in CD14-deficient mice was at least threefold higher than in control mice after injection of either unencapsulated or encapsulated S. aureus, suggesting that CD14 down-regulates TNF-α. A similar increase in serum TNF-α occurred when CD14-deficient animals were injected with gentamicin-killed bacteria even though no symptoms of shock were observed. These studies indicate that CD14, in contrast to its key function in responses to the Gram-negative bacterium, Escherichia coli 0111, does not play a prominent role in septic shock induced by S. aureus, and that the symptoms of S. aureus shock are not due solely to TNF-α.

CD14 Downregulate the TNF-α Response, but Plays No Major Role in Shock Induced by Group B Streptococcus Infection

CD14 Downregulate the TNF-α Response, but Plays No Major Role in Shock Induced by Group B Streptococcus Infection