3,271 research outputs found
Unemployment, hysteresis and transition
We quantify the degree of persistence in unemployment rates of transition countries using a variety of methods benchmarked against the EU. In part of the paper, we work with the concept of linear "Hysteresis" as described by the presence of unit roots in unemployment. Since this is potentially a narrow definition, we also take into account the existence of structural breaks and non-linear dynamics in unemployment. Finally, we examine whether CEECs' unemployment presents features of multiple equilibria: if it remains locked into a new level whenever a structural change occurs. Our findings show that, in general, we can reject the unit root hypothesis after controlling for structural changes and business cycle effects, but we can observe the presence of a high and low unemployment equilibria. The speed of adjustment is faster for CEECs than the EU, although CEECs tend to move more frequently between equilibria. JEL Classification: E24, C22, C23Hysteresis, Markov switching, Transition, Unemployment, Unit Root
Identifying the elasticity of substitution with biased technical change
Despite being critical parameters in many economic fields, the received wisdom, in theoretical and empirical literatures, states that joint identification of the elasticity of capital-labor substitution and technical bias is infeasible. This paper challenges that pessimistic interpretation. Putting the new approach of "normalized" production functions at the heart of a Monte Carlo analysis we identify the conditions under which identification is feasible and robust. The key result is that the jointly modeling the production function and first-order conditions is superior to single-equation approaches in terms of robustly capturing production and technical parameters, especially when merged with "normalization". Our results will have fundamental implications for production-function estimation under non-neutral technical change, for understanding the empirical relevance of normalization and the variability underlying past empirical studies. JEL Classification: C22, E23, O30, 051Constant Elasticity of Substitution, Factor Income share, Factor-Augmenting Technical Change, Identification, Monte Carlo, Normalization
In dubio pro CES - Supply estimation with mis-specified technical change
Capital-labor substitution and total factor productivity (TFP) estimates are essential features of growth and income distribution models. In the context of a Monte Carlo exercise embodying balanced and near balanced growth, we demonstrate that the estimation of the substitution elasticity can be substantially biased if the form of technical progress is misspecified. For some parameter values, when factor shares are relatively constant, there could be an inherent bias towards Cobb-Douglas. The implied estimates of TFP growth also yield substantially different results depending on the specification of technical progress. A Constant Elasticity of Substitution production function is then estimated within a “normalized” system approach for the US economy over 1960:1–2004:4. Results show that the estimated substitution elasticity tends to be significantly lower using a factor augmenting specification (well below one). We are able to reject Hicks-, Harrod- and Solow-neutral specifications in favor of general factor augmentation with a non-negligible capital-augmenting component. Finally, we draw some important lessons for production and supply-side estimation. JEL Classification: C15, C32, E23, O33, O51Balanced Growth, Constant Elasticity of Substitution, Factor Income share, Factor-Augmenting Technical Change, Technical Progress Neutrality
Frequency-dependent and correlational selection pressures have conflicting consequences for assortative mating in a color-polymorphic lizard, Uta stansburiana
Acknowledgments We would like to thank the numerous undergraduate researchers involved with this project for their invaluable assistance in lizard rearing and data collection. We also thank D. Haisten, A. Runemark, Y. Takahashi, and M. Verzijden for insightful comments on the manuscript. This project was funded by National Science Foundation DEBOS-15973 to A.G.M. and B.R.S.Peer reviewedPublisher PD
Development of on-line FTIR spectroscopy for siloxane detection in biogas to enhance carbon contactor management
Activated carbon filters are used to limit engine damage by siloxanes when biogas is utilised to provide electricity. However, carbon filter siloxane removal performance is poorly understood as until recently, it had not been possible to measure siloxanes on-line. In this study, on-line Fourier Transform Infrared (FTIR) spectroscopy was developed to measure siloxane concentration in real biogas both upstream (86.1–157.5 mg m−3) and downstream (2.2–4.3 mg m−3) of activated carbon filters. The FTIR provided reasonable precision upstream of the carbon vessel with a root mean square error of 10% using partial least squares analysis. However, positive interference from volatile organic carbons was observed in downstream gas measurements limiting precision at the outlet to an RMSE of 1.5 mg m−3 (47.8%). Importantly, a limit of detection of 3.2 mg m−3 was identified which is below the recommended siloxane limit and evidences the applicability of on-line FTIR for this application
Imminence in Refugee and Human Rights Law: A Misplaced Notion for International Protection
This article is the first scholarly output of a major research project examining the notion of imminence in the law on international protection. It is the first piece of scholarship to identify an emerging trend, namely the introduction of imminence—whether invoked implicitly or explicitly—as a potential barrier to refugee status or complementary protection. The article analyses the jurisprudence of relevant international bodies and courts and critiques the validity of this notion as a tool for assessing States’ protection obligations
The Role of (Delta)C-13 in the Search for Reduced Organics on the Surface of Mars
The capabilities of the Sample Analysis at Mars (SAM) instrument suite on the Mars Science Laboratory (MSL) to detect trace amounts of organic carbon compounds are unprecedented, and MSL may be the first mission to reveal the presence of organic carbon on Mars. The search for reduced organic carbon on Mars is inextricably tied to: a) the preservation potential of the environment from which we take a solid sample, and b) the evolved gas analysis (EGA) techniques used by SAM to release volatiles from this solid sample. Several prospective targets have been identified for sample analysis at Gale Crater. Stratigraphic sequences of phyllosilicates and sulfates at Gale are thought to represent a period of global climate transition from a moderate pH lacustrine environment to an evaporitic environment, both of which could sequester organic carbon (Thomson et al. 2011). The sediment mound in Gale Crater contains a range of lithologies suggesting changes in redox conditions, and evidence of both lacustrine and fluvial depositional processes, which may have transported organic carbon from the layer in which it formed and resulted in its preservation elsewhere within the crater (Anderson and Bell, 2010). Inverted channel fills suggest erosion resistant material that could serve to preserve organics originally deposited in a low energy aqueous environment. The lithology sampled will affect not only the preservation of organics, but also our ability to detect organics during our evolved gas analysis, based on the sample matrix. For example, reduced organics may be trapped in the mineral structure, and thermal evolution of these organics will occur during thermal decomposition of the host mineral. If organics are occluded in minerals that have very high thermal decomposition temperatures, they may be, in effect, "too well preserved," and difficult to detect during EGA. Alternatively, the possible presence of perchlorate, or other strong oxidants in surface regolith, may result in destruction of structural information identifying organic molecules before reaching the QMS on SAM via oxidation to C02 during heating. If this is the case, the stable carbon isotopic composition (delta 13C) of the C02 evolved and measured by the Tunable Laser Spectrometer (TLS) on SAM may help identify the presence of organics. On Earth, biological activity can cause large fractionations of 13C/12C, which can preserved in sedimentary deposits and distinguish the organic products of biotic processes from inorganic atmospheric and geological reservoirs. It is plausible that similar fractionations could occur on Mars and be preserved in reduced organic matter in sediments. Bulk delta 13C measurements alone may not reveal a signature of trace organic carbon that may be present along with inorganic carbon. If both organic and inorganic carbon compounds are present, it may be possible to detect the organic carbon by comparing the 013C of pyrolysis and combustion experiments. The TLS on SAM is capable of obtaining high precision measurements of delta13C from C02 evolved during pyrolysis and combustion of solid regolith samples. Because carbonates are expected to be present at abundances of 0.1-1 % in Martian soil, and organics in the ppb range (Webster and Mahaffy, 2011), analog samples must represent this mix of reduced organic carbon and carbonate. The work presented here will examine the use of delta13C of C02 produced during combustion of bulk Mars analog samples as a proxy for detection of reduced organic carbon
The recurrent evolution of extremely resistant xylem
International audienceAbstractKey messageHighly resistant xylem has evolved multiple times over the past 400 million years.ContextWater is transported under tension in xylem and consequently is vulnerable to invasion by air and the formation of embolism. A debate has raged over whether embolism formation is non-reversible occurring at low water potentials or a regular diurnal occurrence that is non-lethal because of a capacity to refill embolised conduits.AimsThis commentary is on a recent article, which utilised new non-invasive imaging techniques for assessing the formation of embolism in xylem, finding that the xylem of Laurus nobilis was highly resistant to the formation of embolism.MethodsThe recent results of this discovery are placed in the context knowledge from a diversity of species that has so far been identified with xylem similarly highly resistant to embolism formation.ResultsThe discovery that L. nobilis has xylem highly resistant to embolism formation adds to a body of literature suggesting that the resistance of xylem to embolism formation is a key adaptation utilised by many species native to seasonally dry environments. Highly resistant xylem has evolved numerous times across the angiosperm clade.ConclusionWith more studies utilising similar observational and direct methods of assessing embolism resistance, further insight into the ecological and evolutionary relevance of this trait is imminent
A well-founded fear of being persecuted ... but when?
It is well established that the ‘well-founded fear’ test in refugee law requires a prospective assessment of potential future harm. Yet, the requisite timeframe involved in this test is rarely examined. Analysis of jurisprudence across a wide range of jurisdictions reveals that Australian courts have been unusually cognisant of the question of timing of harm. Indeed, they have been particularly insistent that a flexible and longer-range assessment is appropriate, encapsulated by the ‘reasonably foreseeable future’ test. This article provides an in-depth analysis of the principles set out by Australian courts, and identifies particularly challenging contexts in which timing has played an important role. It also assesses the extent to which decision-makers at the tribunal level adhere to the flexible approach formulated by the judiciary. It is hoped that our analysis of Australian jurisprudence may prove helpful in other jurisdictions in which the issue of timing of harm is equally pertinent but far less developed
Evaluation of a rehabilitation support service after acute stroke: Feasibility and patient/carer benefit
Background: Stroke survivors returning home after discharge from hospital and their carers require support to meet their rehabilitation needs (independence in Activities of Daily Living, exercise, psychosocial support). Voluntary or charitable care providers may be able to address some of these needs.
Objective: To explore the feasibility of delivering and evaluating enhanced support to stroke survivors and their carers, with a Rehabilitation Support Worker (RSW).
Methods: 16 consecutive stroke survivors and their carers were included. All participants received usual hospital care. Seven of these patients and their carers were also allocated an RSW from a charitable care provider. The RSW accompanied therapy training sessions with the patient, carer and therapist in hospital. On discharge, the RSW visited the patient and carer at home over the initial 6 week post-discharge period to support them in practising rehabilitation skills. Patient function (Barthel Index) and patient/carer confidence were independently assessed at discharge (Week 0). The above assessments and patient/carer mood (GHQ-12) and Carer Giver Strain were also assessed at Weeks 1, 6 and 12. RSWs were interviewed for their views about the service.
Results: Participants’ functional ability at Week 1 post-discharge was significantly higher in the RSW group. At 6 and 12 weeks post-discharge, functional ability was not significantly different between groups. Carers in the intervention group were less confident at all time points, however, this was not significant. There was no significant effect on carer strain or well-being. Interviews with RSWs highlighted areas of their training that could be enhanced and the need for greater clarity as to their role.
Conclusions: The results showed that a definitive trial of rehabilitation support is feasible. A number of obstacles however would need to be overcome including: difficulty in identifying suitable patients, clarity of the RSW role, and appropriate training content
- …