Risk Shocks Christiano, Lawrence J.; Motto, Roberto; Rostagno, Massimo
The American economic review,
01/2014, Letnik:
104, Številka:
1
Journal Article
Recenzirano
We augment a standard monetary dynamic general equilibrium model to include a Bernanke-Gertler-Gilchrist financial accelerator mechanism. We fit the model to US data, allowing the volatility of ...cross-sectional idiosyncratic uncertainty to fluctuate over time. We refer to this measure of volatility as risk. We find that fluctuations in risk are the most important shock driving the business cycle.
Markets: The Credit Rating Agencies White, Lawrence J.
The Journal of economic perspectives,
04/2010, Letnik:
24, Številka:
2
Journal Article
Recenzirano
Odprti dostop
This paper will explore how the financial regulatory structure propelled three credit rating agencies—Moody's, Standard & Poor's (S&P), and Fitch—to the center of the U.S. bond markets—and thereby ...virtually guaranteed that when these rating agencies did make mistakes, these mistakes would have serious consequences for the financial sector. We begin by looking at some relevant history of the industry, including the series of events that led financial regulators to outsource their judgments to the credit rating agencies (by requiring financial institutions to use the specific bond creditworthiness information that was provided by the major rating agencies) and when the credit rating agencies shifted their business model from “investor pays” to “issuer pays.” We then look at how the credit rating industry evolved and how its interaction with regulatory authorities served as a barrier to entry. We then show how these ingredients combined to contribute to the subprime mortgage debacle and associated financial crisis. Finally, we consider two possible routes for public policy with respect to the credit rating industry: One route would tighten the regulation of the rating agencies, while the other route would reduce the required centrality of the rating agencies and thereby open up the bond information process in way that has not been possible since the 1930s.
A populist backlash to globalization has ushered in nationalist governments and challenged core features of the Liberal International Order. Although startling in scope and urgency, the populist wave ...has been developing in declining regions of wealthy countries for some time. Trade, offshoring, and automation have steadily reduced the number of available jobs and the wages of industrial workers since at least the 1970s. The decline in manufacturing employment initiated the deterioration of social and economic conditions in affected communities, exacerbating inequalities between depressed rural areas and small cities and towns, on the one hand, and thriving cities, on the other. The global financial crisis of 2008 catalyzed these divisions, as communities already in decline suffered deeper and longer economic downturns than metropolitan areas, where superstar knowledge, technology, and service-oriented firms agglomerate. We document many of these trends across the United States and Europe, and demonstrate that populist support is strongest in communities that experienced long-term economic and social decline. Institutional differences in labor markets and electoral rules across developed democracies may explain some of the variation in populists’ electoral success. Renewed support for the Liberal International Order may require a rejuvenation of distressed communities and a reduction of stark regional inequalities.
Cardiovascular disease (CVD) is the leading global cause of death, accounting for 17.3 million deaths per year. Preventive treatment that reduces CVD by even a small percentage can substantially ...reduce, nationally and globally, the number of people who develop CVD and the costs of caring for them. This American Heart Association presidential advisory on dietary fats and CVD reviews and discusses the scientific evidence, including the most recent studies, on the effects of dietary saturated fat intake and its replacement by other types of fats and carbohydrates on CVD. In summary, randomized controlled trials that lowered intake of dietary saturated fat and replaced it with polyunsaturated vegetable oil reduced CVD by ≈30%, similar to the reduction achieved by statin treatment. Prospective observational studies in many populations showed that lower intake of saturated fat coupled with higher intake of polyunsaturated and monounsaturated fat is associated with lower rates of CVD and of other major causes of death and all-cause mortality. In contrast, replacement of saturated fat with mostly refined carbohydrates and sugars is not associated with lower rates of CVD and did not reduce CVD in clinical trials. Replacement of saturated with unsaturated fats lowers low-density lipoprotein cholesterol, a cause of atherosclerosis, linking biological evidence with incidence of CVD in populations and in clinical trials. Taking into consideration the totality of the scientific evidence, satisfying rigorous criteria for causality, we conclude strongly that lowering intake of saturated fat and replacing it with unsaturated fats, especially polyunsaturated fats, will lower the incidence of CVD. This recommended shift from saturated to unsaturated fats should occur simultaneously in an overall healthful dietary pattern such as DASH (Dietary Approaches to Stop Hypertension) or the Mediterranean diet as emphasized by the 2013 American Heart Association/American College of Cardiology lifestyle guidelines and the 2015 to 2020 Dietary Guidelines for Americans.
It is vital to acknowledge the socio-political complexity of the deployment of the term 'resilience' and to develop a more unified set of expectations for the professions and disciplines that use it. ...Applied to cities, resilience is particularly problematic, yet also retains promise. Like resilience, the term 'city' is also subject to multiple contending definitions, depending on the scale and on whether the focus is on physical spaces or social communities. Due to cities and city-regions being organized in ways that both produce and reflect underlying socio-economic disparities, some parts are much more resilient than others and therefore vulnerability is often linked to both topography and income. Uneven resilience threatens the ability of cities as a whole to function economically, socially and politically. Resilience can only remain useful as a concept and as progressive practice if it is explicitly associated with the need to improve the life prospects of disadvantaged groups. This dimension is often lost in definitions of resilience drawn from engineering and ecology, but remains central to conceptualizations linked to social psychology. To improve the prospects of cities proactively (and reactively), there is a need to unify the insights from the multiple professions and disciplines that use 'resilience'.
The vital roles that intestinal flora, now called microbiota, have in maintaining our health are being increasingly appreciated. Starting with birth, exposure to the outside world begins the ...life-long intimate association our microbiota will have with our diet and environment, and initiates determination of the post-natal structural and functional maturation of the gut. Moreover, vital interactions of the microbiota with our metabolic activities, as well as with the immunological apparatus that constitutes our major defense system against foreign antigens continues throughout life. A perturbed intestinal microbiome has been associated with an increasing number of gastrointestinal and non-gastrointestinal diseases including Clostridium difficile infection (CDI). It has become recognized that fecal microbiota transplantation (FMT) can correct the dysbiosis that characterizes chronic CDI, and effect a seemingly safe, relatively inexpensive, and rapidly effective cure in the vast majority of patients so treated. In addition, FMT has been used to treat an array of other gastrointestinal and non-gastrointestinal disorders, although experience in these other non-CDI diseases is in its infancy. More work needs to be done with FMT to ensure its safety and optimal route of administration. There is a conceptual sea change that is developing in our view of bacteria from their role only as pathogens to that of being critical to health maintenance in a changing world. Future studies are certain to narrow the spectrum of organisms that need to be given to patients to cure disease. FMT is but the first step in this journey.
Three neuromodulation therapies have been appropriately tested and approved in refractory focal epilepsies: vagus nerve stimulation (VNS), deep brain stimulation of the anterior nucleus of the ...thalamus (ANT-DBS), and closed-loop responsive neurostimulation of the epileptogenic zone or zones. These therapies are primarily palliative. Only a few individuals have achieved complete freedom from seizures for more than 12 months with these therapies, whereas more than half have benefited from long-term reduction in seizure frequency of more than 50%. Implantation-related adverse events primarily include infection and pain at the implant site. Intracranial haemorrhage is a frequent adverse event for ANT-DBS and responsive neurostimulation. Other stimulation-specific side-effects are observed with VNS and ANT-DBS. Biomarkers to predict response to neuromodulation therapies are not available, and high-level evidence to aid decision making about when and for whom these therapies should be preferred over other antiepileptic treatments is scant. Future studies are thus needed to address these shortfalls in knowledge, approve other forms of neuromodulation, and develop personalised closed-loop therapies with embedded machine learning. Until then, neuromodulation could be considered for individuals with intractable seizures, ideally after the possibility of curative surgical treatment has been carefully assessed and ruled out or judged less appropriate.
Lawrence J. Vale's groundbreaking book is both a comprehensive institutional history of public housing in Boston and a broader examination of the nature and extent of public obligation to house ...socially and economically marginal Americans during the past 350 years.
A
bstract
A
Z
2
symmetry that extends the weak interaction, SU(2)
L
→ SU(2)
L
×SU(2)
′
, and the Higgs sector,
H
(2) →
H
(2
,
1) +
H
′
(1
,
2), yields a Standard Model quartic coupling that vanishes ...at scale
v
′
= 〈
H
′
〉 ≫ 〈
H
〉. Near
v
′
, theories either have a “prime” sector, or possess “Left-Right” (LR) symmetry with SU(2)
′
= SU(2)
R
. If the
Z
2
symmetry incorporates spacetime parity, these theories can solve the strong CP problem. The LR theories have all quark and lepton masses arising from operators of dimension 5 or more, requiring Froggatt-Nielsen structures. Two-loop contributions to
θ
¯
are estimated and typically lead to a neutron electric dipole moment of order 10
−27
e cm that can be observed in future experiments. Minimal models, with gauge group SU(3) × SU(2)
L
× SU(2)
L
× U(1)
B
−
L
, have precise gauge coupling unification for
v
′
= 10
10±1
GeV, successfully correlating gauge unification with the observed Higgs mass of 125 GeV. With SU(3) × U(1)
B
−
L
embedded in SU(4), the central value of the unification scale is reduced from 10
16−17
GeV to below 10
16
GeV, improving the likelihood of proton decay discovery. Unified theories based on SO(10) ×
CP
are constructed that have
H
+
H
′
in a
16
or
144
and generate higher-dimensional flavor operators, while maintaining perturbative gauge couplings.
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