1,955 research outputs found

    Price setting behaviour in Spain: evidence from micro PPI data

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    This paper identifies the basic features of price setting behaviour at the producer level in the Spanish economy using a large dataset containing the micro data underlying the construction of the PPI over the period 1991-1999. It explores how these general features are affected by some specific factors (cost structure, degree of competition, demand conditions, government intervention, level of inflation, seasonality, and the practice of using attractive prices) and presents a comparison of price setting practices at the producer and at the consumer level to ascertain whether the retail sector augments or mitigates price stickiness. We find that prices do not change often but do so by a large amount. The cost structure, proxied by the labour share and the relevance of raw materials, and the degree of competition, proxied by import penetration, affect price flexibility. We also find some evidence that producer prices are more flexible than consumer prices. JEL Classification: E31, D40frequency of price changes, price setting, producer prices

    Do decreasing hazard functions for price changes make any sense?

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    A common finding in empirical studies using micro data on consumer and producer prices is that hazard functions for price changes are decreasing. This means that a firm will have a lower probability of changing its price the longer it has kept it unchanged. This result is at odds with standard models of price setting. Here a simple explanation is proposed: decreasing hazards may result from aggregating heterogeneous price setters. We show analytically the form of this heterogeneity effect for the most commonly used pricing rules and find that the aggregate hazard is (nearly always decreasing. Results are illustrated using Spanish producer and consumer price data. We find that a very accurate representation of individual data is obtained by considering just 4 groups of agents: one group of flexible Calvo agents, one group of intermediate Calvo agents and one group of sticky Calvo agents plus an annual Calvo process. JEL Classification: C40, D40, E30hazard function, Heterogeneous Agents, mixture models, price setting models

    cdcatR: An R package for cognitive diagnostic computerized adaptive testing

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    Cognitive diagnosis models (CDMs) are confirmatory latent class models that provide fine-grained information about skills and cognitive processes. These models have gained attention in the last few years because of their usefulness in educational and psychological settings. Recently, numerous developments have been made to allow for the implementation of cognitive diagnosis computerized adaptive testing (CD-CAT). Despite methodological advances, CD-CAT applications are still scarce. To facilitate research and the emergence of empirical applications in this area, we have developed the cdcatR package for R software. The purpose of this document is to illustrate the different functions included in this package. The package includes functionalities for data generation, model selection based on relative fit information, implementation of several item selection rules (including item exposure control), and CD-CAT performance evaluation in terms of classification accuracy, item exposure, and test length. In conclusion, an R package is made available to researchers and practitioners that allows for an easy implementation of CD-CAT in both simulation and applied studies. Ultimately, this is expected to facilitate the development of empirical applications in this areaThis research was funded by Ministerio de Ciencia e Innovación, grant number PSI2017- 85022-P, and Cåtedra de Modelos y Aplicaciones Psicométricas (Instituto de Ingeniería del Conocimiento and Autonomous University of Madrid

    Aportaciones a la flora vascular de la provincia de Córdoba, II (Andalucía, España)

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    En el presente estudio corolĂłgico se aportan 25 taxones que son raros o suponen novedad para alguna comarca o toda la provincia de CĂłrdoba (AndalucĂ­a, España). Los taxones mĂĄs interesantes son Campanula decumbens subsp. baetica Cano-Maqueda & Talavera, Narcissus × susannae Fern. Casas y Plumbago auriculata Lam., ya que son citados por primera vez para esta provincia.Twenty-five taxa are recorded as rare and new localities either in some areas or the whole province of Cordoba (Andalusia, Spain). Campanula decumbens subsp. baetica Cano-Maqueda & Talavera, Narcissus × susannae Fern. Casas and Plumbago auriculata Lam. are the most interesting taxa found, being the first record for this province

    The pine shoot beetle Tomicus piniperda as a plausible vector of Fusarium circinatum in northern Spain

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    International audienceAbstractKey messageThe pine shoot beetle, Tomicus piniperda, is a potential vector of the pitch canker disease pathogen. The insect could transmit the pathogenic fungus during its maturation or regeneration feeding on the shoots of healthy pine crowns.ContextFusarium circinatum, the causal agent of pitch canker disease, currently affects Pinus radiata in northern Spain, causing pitch-soaked cankers and tree death. Although several species of the family Scolytinae have been reported as vectors of this pathogen, the role of the pine shoot beetle T. piniperda remains unclear.AimsThe general objective of this study was to determine whether T. piniperda is a vector for the pitch canker pathogen F. circinatum. For this purpose, Leach’s postulates (1) an association between T. piniperda and trees affected by pitch canker disease; (2) regular visits by T. piniperda to healthy P. radiata trees; (3) presence of the pathogen on the insect in nature; and (4) transmission of the pathogen to disease-free host material under controlled conditions.MethodsFresh green shoots with feeding galleries were collected from the ground, breeding galleries were collected from diseased trunks and insects were collected during their dispersion flights. A laboratory experiment was conducted in which specimens of T. piniperda were inoculated with the pathogen prior to feeding on shoots.ResultsIn the field, T. piniperda was found to be associated with both diseased and healthy P. radiata trees, and F. circinatum was found to be present, at low rates, on the exoskeleton of T. piniperda. In the laboratory experiment, evidence of the ability of T. piniperda to transfer the pathogen to healthy shoots was found.ConclusionsThe study findings indicate T. piniperda as a plausible vector of this pathogen. We postulate for the first time a potential relationship between the life cycles of T. piniperda and F. circinatum

    Thread-like tentacles in the Mediterranean corals Paramuricea clavata and Corallium rubrum

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    The occurrence of modified tentacles (i.e. thread-like tentacles) in the Mediterranean octocorals Paramuricea clavata and Corallium rubrum is reported. Colonies of four species of Mediterranean gorgonians were maintained in aquarium conditions for more than 5 months. The development of thread-like tentacles has been observed only in two of the four species. The presence of modified tentacles in other cnidarians has been usually associated with defensive/aggressive behavior. Our observations showed that thread-like tentacles in P. clavata and C. rubrum can also be used for feeding
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