4,144 research outputs found
Sovereign default and monetary policy tradeoffs
The paper is organized around the following question: when the economy moves from a debt-GDP level where the probability of default is nil to a higher levelâthe âfiscal limitââwhere the default probability is non-negligible, how do the effects of routine monetary operations designed to achieve macroeconomic stabilization change? We find that the specification of the monetary policy rule plays a critical role. Consider a central bank that targets the risky rate. When the economy is near its fiscal limit, a transitory monetary policy contraction leads to a sustained rise in inflation, even though monetary policy actively targets inflation and fiscal policy passively adjusts taxes to stabilize debt. If the central bank targets the riskfree rate, on the other hand, the same transitory monetary contraction keeps inflation under control but leads output to contract for a prolonged period of time. The comparison shows that sovereign default risk puts into sharp relief the tradeoff between inflation and output stabilization
Uncertain Fiscal Consolidations
The paper explores the macroeconomic consequences of fiscal consolidations whose timing and composition are uncertain. Drawing on the evidence in Alesina and Ardagna (2010), we emphasize whether or not the fiscal consolidation is driven by tax rises or expenditure cuts. We find that the composition of the fiscal consolidation, its duration, the monetary policy stance, the level of government debt and expectations over the likelihood and composition of fiscal consolidations all matter in determining the extent to which a given consolidation is expansionary and/or successful in stabilizing government debt.government debt, budget reform, monetary-fiscal policy interactions
Uncertain Fiscal Consolidations
The paper explores the macroeconomic consequences of fiscal consolidations whose timing and composition are uncertain. Drawing on the evidence in Alesina and Ardagna (2010), we emphasize whether or not the fiscal consolidation is driven by tax rises or expenditure cuts. We find that the composition of the fiscal consolidation, its duration, the monetary policy stance, the level of government debt and expectations over the likelihood and composition of fiscal consolidations all matter in determining the extent to which a given consolidation is expansionary and/or successful in stabilizing government debt.
Giving voters what they want? Party orientation perceptions and preferences in the British electorate
Some of the most important propositions in the political marketing literature hinge on assumptions about the electorate. In particular, voters are presumed to react in different ways to different orientations or postures. Yet there are theoretical reasons for questioning some of these assumptions, and certainly they have seldom been empirically tested. Here, we focus on one prominent example of political marketing research: Lees-Marshmentâs orientationsâ model. We investigate how the public reacts to product and market orientation, whether they see a trade-off between the two (a point in dispute among political marketing scholars), and whether partisans differ from non-partisan voters by being more inclined to value product over market orientation. Evidence from two mass sample surveys of the British public (both conducted online by YouGov) demonstrates important heterogeneity within the electorate, casts doubt on the core assumptions underlying some political marketing arguments and raises broader questions about what voters are looking for in a party
Uncertain fiscal consolidations
The paper explores the macroeconomic consequences of fiscal consolidations whose timing and composition are uncertain. Drawing on the evidence in Alesina and Ardagna (2010), we emphasize whether or not the fiscal consolidation is driven by tax rises or expenditure cuts. We find that the composition of the fiscal consolidation, its duration, the monetary policy stance, the level of government debt and expectations over the likelihood and composition of fiscal consolidations all matter in determining the extent to which a given consolidation is expansionary and/or successful in stabilizing government debt
âTrying to pin down jellyâ - exploring intuitive processes in quality assessment for meta-ethnography
Background:
Studies that systematically search for and synthesise qualitative research are becoming more evident in health care, and they can make an important contribution to patient care. However, there is still no agreement as to whether, or how we should appraise studies for inclusion. We aimed to explore the intuitive processes that determined the âqualityâ of qualitative research for inclusion in qualitative research syntheses. We were particularly interested to explore the way that knowledge was constructed.
Methods:
We used qualitative methods to explore the process of quality appraisal within a team of seven qualitative researchers funded to undertake a meta-ethnography of chronic non-malignant musculoskeletal pain. Team discussions took place monthly between October 2010 and June 2012 and were recorded and transcribed. Data was coded and organised using constant comparative method. The development of our conceptual analysis was both iterative and collaborative. The strength of this team approach to quality came from open and honest discussion, where team members felt free to agree, disagree, or change their position within the safety of the group.
Results:
We suggest two core facets of quality for inclusion in meta-ethnography - (1) Conceptual clarity; how clearly has the author articulated a concept that facilitates theoretical insight. (2) Interpretive rigour; fundamentally, can the interpretation âbe trusted?â Our findings showed that three important categories help the reader to judge interpretive rigour: (ii) What is the context of the interpretation? (ii) How inductive is the interpretation? (iii) Has the researcher challenged their interpretation?
Conclusions:
We highlight that methods alone do not determine the quality of research for inclusion into a meta-ethnography. The strength of a concept and its capacity to facilitate theoretical insight is integral to meta-ethnography, and arguably to the quality of research. However, we suggest that to be judged âgood enoughâ there also needs to be some assurance that qualitative findings are more than simply anecdotal. Although our conceptual model was developed specifically for meta-ethnography, it may be transferable to other research methodologies
Mechanical Stress Inference for Two Dimensional Cell Arrays
Many morphogenetic processes involve mechanical rearrangement of epithelial
tissues that is driven by precisely regulated cytoskeletal forces and cell
adhesion. The mechanical state of the cell and intercellular adhesion are not
only the targets of regulation, but are themselves likely signals that
coordinate developmental process. Yet, because it is difficult to directly
measure mechanical stress {\it in vivo} on sub-cellular scale, little is
understood about the role of mechanics of development. Here we present an
alternative approach which takes advantage of the recent progress in live
imaging of morphogenetic processes and uses computational analysis of high
resolution images of epithelial tissues to infer relative magnitude of forces
acting within and between cells. We model intracellular stress in terms of bulk
pressure and interfacial tension, allowing these parameters to vary from cell
to cell and from interface to interface. Assuming that epithelial cell layers
are close to mechanical equilibrium, we use the observed geometry of the two
dimensional cell array to infer interfacial tensions and intracellular
pressures. Here we present the mathematical formulation of the proposed
Mechanical Inverse method and apply it to the analysis of epithelial cell
layers observed at the onset of ventral furrow formation in the {\it
Drosophila} embryo and in the process of hair-cell determination in the avian
cochlea. The analysis reveals mechanical anisotropy in the former process and
mechanical heterogeneity, correlated with cell differentiation, in the latter
process. The method opens a way for quantitative and detailed experimental
tests of models of cell and tissue mechanics
Using PIV to measure granular temperature in saturated unsteady polydisperse granular flows
The motion of debris flows, gravity-driven fast
moving mixtures of rock, soil and water can be interpreted
using the theories developed to describe the shearing motion
of highly concentrated granular fluid flows. Frictional, collisional
and viscous stress transfer between particles and
fluid characterizes the mechanics of debris flows. To quantify
the influence of collisional stress transfer, kinetic models
have been proposed. Collisions among particles result in random
fluctuations in their velocity that can be represented by
their granular temperature, T. In this paper particle image
velocimetry, PIV, is used to measure the instantaneous velocity
field found internally to a physical model of an unsteady
debris flow created by using âtransparent soilââi.e. a mixture
of graded glass particles and a refractively matched fluid.
The ensemble possesses bulk properties similar to that of
real soil-pore fluid mixtures, but has the advantage of giving
optical access to the interior of the flow by use of plane laser
induced fluorescence, PLIF. The relationship between PIV
patch size and particle size distribution for the front and tail
of the flows is examined in order to assess their influences
on the measured granular temperature of the system. We find
that while PIV can be used to ascertain values of granular
temperature in dense granular flows, due to increasing spatial
correlation with widening gradation, a technique proposed to
infer the true granular temperature may be limited to flows
of relatively uniform particle size or large bulk
Symmetry broken vectorial Kerr frequency combs from Fabry-PĂ©rot resonators
Spontaneous symmetry breaking of a pair of vector temporal cavity solitons has been established as a paradigm to modulate optical frequency combs, and finds many applications in metrology, frequency standards, communications, and photonic devices. While this phenomenon has successfully been observed in Kerr ring resonators, the counterpart exploiting linear Fabry-PĂ©rot cavities is still unexplored. Here, we consider field polarization properties and describe a vector comb generation through the spontaneous symmetry breaking of temporal cavity solitons within coherently driven, passive, Fabry-PĂ©rot cavities with Kerr nonlinearity. Global coupling effects due to the interactions of counter-propagating light restrict the maximum number of soliton pairs within the cavity - even down to a single soliton pair - and force long range polarization conformity in trains of vector solitons
A hybrid, auto-adaptive, and rule-based multi-agent approach using evolutionary algorithms for improved searching
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